REPORT
OF THE
COMMITTEE
OF INQUIRY ON
FOOT-and-Mouth
Disease
1968
PART ONE
Presented to Parliament by the Minister of Agriculture, Fisheries and
Food
By Command of her
Majesty
April
1969
LONDON
HER MAJESTYS STATIONERY OFFICE
15s od. Net
Cmnd. 3999
COMMITTEE OF INQUIRY
ON
FOOT-AND-MOUTH DISEASE
MINUTE OF
APPOINTMENT
I hereby appoint
The Duke of Northumberland, K.G.,T.D., J.P.
A. Cripps,
Esq., D.S.O., T.D., Q.C.
Professor D. G. Evans, D.Sc.,
Ph.D., F.C. Path., F.R.S.
C.H. Plumb, Esq.
Sir Edward Thompson, M.B.E.,
T.D.
Professor D. Walker, M.A.
Professor Sir William L. Weipers,
B.Sc., F.R.C.V.S., D.V.S.M.,
F.R.S.E.
to be a Committee to review the
policy and arrangements for dealing with
foot-and-mouth disease in
Great Britain and to make recommendations.
I further appoint the Duke of
Northumberland to be Chairman of the Committee
and Mr. J.N. Jotchman to be Secretary, and Mrs. M.D. White
to be Assistant Secretary of the Committee.
(Sgd.) FREDERICK
PEART
Minister of
Agriculture, Fisheries and Food.
28th February, 1968
In addition to
the above I hereby appoint
E.L. Thomas,
Esq., L.L.B., J.P.
to be an additional member of the
Committee.
(Sgd.) CLEDWYN
HUGHES
Minister of Agriculture, Fisheries and Food.
22nd April, 1968.
2
PART 1 OF THE REPORT OF THE COMMITTEE
OF
INQUIRY ON FOOT-AND-MOUTH
DISEASE
To the
Rt. Hon. CLEDWYN HUGHES, M.P.
Minister of Agriculture, Fisheries and
Food.
Sir,
We were appointed on 28th
February, 1968:-
to review
the policy and arrangements for dealing with foot-and-mouth disease in Great
Britain and to make recommendations.
We now have the honour to submit Part I
of our Report.
We have
given priority to consideration of the ways by which the risk of the introduction of foot-and-mouth disease
virus into Great Britain, and the risk
of
future epidemics, might be reduced. Our major task has therefore been to
accumulate and evaluate the available scientific evidence and to weigh up the
advantages and disadvantages of various possible policies. We have held 29
meetings
in this country and have visited Denmark, France, the Federal Republic of
Germany, the Netherlands, Argentina, Brazil and Uruguay. The objects of these
visits were to hold general discussions on foot-and-mouth disease and to
familiarize ourselves with control programmes and the disease situation in these
countries. We also visited the Centro Pan-Americano de Febre Aftosa in Rio de
Janeiro and we met officials of the United States De-partment of Agriculture in
Washington and at the Plum Island Animal Disease Laboratory, Long Island, New
York. We received evidence from the Food and Agriculture
Organisation of the United Nations and from the Office International des
Epizooties. Many countries helped us by supplying infor-mation which we had
requested. A large number of organisations and
individuals in this country submitted written evidence, and with some of
these we have discussed their memoranda. A list of those persons and bodies from
whom we have received evidence is in Appendix I.
We wish to thank all our witnesses
in this country for the efforts they made on our behalf. Also we are greatly
indebted to all those who played a part in the
arrangements for our visits to Europe and to North and South America. We deeply
appreciate the kindness and courtesy with which we were received, and the frank
and full assistance given to us in the conduct of our
inquiries.
We
interpret our terms of reference as demanding the fullest possible infor-mation
we can provide about foot-and-mouth disease and its control and that it is not
for us to attempt to express judgments on the social, political and commercial
implications of the policy we recommend.
Part I of
our Report gives general information about foot-and-mouth disease and deals with
measures designed to reduce the incidence of primary outbreaks and the
risks of such outbreaks giving rise to epidemics. There remain matters of
detailed arrangements if outbreaks occur, including compensation and valuation,
which will be the subject of our recommendations in Part II; on these matters we
shall be taking further evidence.
A
summary of our recommendations is given in Chapter VIII. Anthony Cripps, Q.C.
does not wholly agree with all these recommendations. The extent of his disagreement is
covered by a Dissenting Note containing his recommendations.
3
Note: The estimated cost of
the Committees inquiries to
31st March 1969, including the Cost of producing Part 1 of the Report, is £13,653 19s. Od. of which £1453 19s. Od. represents
the estimated cost of printing and publication.
4
PART 1 OF THE REPORT OF THE COMMITTEE
OF
INQUIRY ON
FOOT-MOUTH-DISEASE
CONTENTS
Chapter
Paragraphs
5
TABLES
Page
6
FIGURES
Page
MAPS
PHOTOGRAPHS
7
APPENDICES
8
CHAPTER
I
INTRODUCTION
1. Foot-and-Mouth
disease is one of the most infectious of all animal diseases. It was first
recorded in Great Britain in 1839 and measures for its control were the subject
of legislation before the end of the nineteenth century. On three occasions in
the past fifty years Committees have been appointed to investigate the cause of
outbreaks in Great Britain and to make recommendations on policy, prevention and
control arrangements.*
2. The present
Committee was appointed following the 1967/1968 epidemic. Our Report, which we
are presenting in two parts, will describe the developments that have taken
place since the Report of the Departmental Committee on Foot-and-Mouth Disease
1952-54 (the Gowers Committee Report). Part I deals with measures designed to
reduce the incidence of primary outbreaks of Foot-and-Mouth Disease in Great
Britain and the risks of such outbreaks giving rise to epidemics. Part II will
deal with such matters as organization, administration, procedures relating to
slaughter and disposal of carcases, sanitary controls, compensation and
valuation. In these matters the Ministry of Agriculture, Fisheries and Food
(referred to subsequently as the Ministry of Agriculture) have the benefit of
long experience, and their record over the years has been one of the
considerable achievement. We therefore think it would be wrong to delay the
recommendations in part I of our Report until the completion of Part II which
will include a review of the detailed control arrangements and ancillary
matters. Inevitably there will be some overlap between the two parts.
*(i) Report of the
Departmental Committee on Foot-and-Mouth Disease, 1922. (Chairman, Captain the
Right Hon. E.G. Pretyman, M.P.)
(Cmd. 1784)
(ii) Report of the Departmental Committee
appointed to consider the outbreak of foot-and-mouth disease which occurred in
1923-1924. (Chairman, Captain the Right Hon. E.G. Pretyman.) (Cmd. 2350.)
(iii) Report of the Departmental
Committee on Foot-and-Mouth Disease 1952-1954. (Chairman, sir Ernest Gowers,
G.B.E., K.C.B.) (Cmd.
9214.)
9
CHAPTER
II
FOOTAND -MOUTH DISEASE AND
ITS
EPIDEMIOLOGY
(a)The Disease
3. We confine ourselves at this point
to the main features of foot-and-mouth disease. A detailed description is given
in Appendix II. The disease is caused by a virus visible only by using the
electron microscope. The virus remains viable under many conditions but it can
be destroyed by heat, direct sunlight, acids and alkalis and some disinfectants.
There are seven known major virus types-
A : C : O : Asia 1 : SAT. 1 : SAT. 2 : SAT. 3
Sub-types occur within these
seven major types and more than fifty sub-types have so far been identified. The
immunological difference between the major types is specific and well defined;
thus animals which have recovered from infection with one type are for some time
immune to that type but they are susceptible to the others. The immunological
difference between some sub- types is slight but between others it may be
considerable. Foot-and-mouth disease virus may display varying characteristics
in relation to infectivity, stability under laboratory tests, severity of the
disease, propensity to attack one species of animal rather than another, power
of survival outside the animal and ability to stimulate immunity.
4. Cloven-hoofed animals are the
natural hosts of foot-and-mouth disease virus. Domestic cattle and pigs are
those which most frequently succumb to attack by the virus, sheep rather
less frequently and goats still less. Wild cloven-hoofed animals are all
apparently susceptible in varying degrees. Hedgehogs have been involved in
outbreaks in this country. Man has on very rare occasions been infected; one
definite case occurred in Northumberland in 1966. It is unlikely, however, that
infection in man plays a part in the spread of the disease. Experimental work
has indicated that rats may carry the virus in their gut for long periods
following ingestion of infected material and are therefore a potential risk but
records do not permit us to conclude whether they can be naturally infected.
Laboratory animals such as guinea-pigs may be infected experimentally but they
do not develop the disease naturally.
5. Animals are infected with
foot-and-mouth disease virus by direct contact with an infected animal. They may
also contract the disease indirectly through contact with material contaminated
by the virus, for example contaminated feedingstuffs or air.
6. The
incubation period after infection varies. It is usually three to eight days but
it can be shorter or it may extend to fourteen days or perhaps more. In typical
cases the disease is readily diagnosed. In cattle, for example, in the early
stages food is refused and lameness follows; salivation, which may be profuse or
slight, occurs and is associated with smacking of the tongue and grinding of the
teeth. Vesicles (blisters), which are usually ruptured, appear on any part of the mucous membrance of the
mouth and occasionally on the udder. The bulb of the heels and the interdigital
spaces are commonly affected.
In
10
young calves, however, the
characteristic clinical appearances and the post-mortem changes may be absent.
In other species there is some variation in the clinical signs of the disease
and in the distribution of lesions
(see Appendix II).
7. Foot-and-mouth disease varies
in its virulence depending on the species of animal affected and on the strain
of virus responsible for the outbreak; it can range from a mild form, which may
be difficult to diagnose clinically, to one of high severity. In general the
death rate from foot-and- mouth disease in adult animals is not high. In Europe,
for example, before the introduction
of the slaughter policy, the death rate in cattle was estimated to be
between one and three per cent. The majority of animals in an infected herd make
a gradual recovery after three or four weeks, but in a dairy herd an economic
production level is seldom reached during the current lactation, and permanent
damage may result, leading to the necessity for heavy culling. The death rate
may be higher in young calves and pigs, and in ewes and lambs during the lambing
season.
8.Foot-and-mouth disease virus may be
present in all parts of the body; it is highly
concentrated in the fluid of the vesicles and it is secreted or excreted in the
milk, saliva, urine and faeces. All secretions and excretions may contain some
virus before the animal has shown signs of the disease and virus may be present
in these after the peak of development of lesions. Animals may become carriers
and harbour the virus for several months after recovery (see paragraphs
42-45).
(b) Epidemiology
9. The incidence of foot-and-mouth
disease varies in different parts of the world (see Chapter III). In some parts
it is completely absent, as in Australia, Canada, Ireland, New Zealand and the
U.S.A.; in others it is present in endemic form as in some parts of South
America; in other parts it occurs only sporadically as in Great Britain (see
Chapter IV).
Endemic, epidemic and
sporadic disease
10. In countries where the disease is
endemic, foot-and-mouth disease virus, causing clinical or sub-clinical
infection, is continuously present in some animals. Thus the virus does not need
to be introduced into these countries to cause an outbreak. Considerable
resistance to infection may be shown by certain indigenous species and the
presence of the disease may not always be obvious. This is especially true of
sheep and also of wild cloven-hoofed animals. Periodically there is an upsurge
of the disease, particularly when the susceptible population of young animals
reaches a high proportion. This could result in an epidemic with widely-spread
outbreaks. At this stage the disease may become more virulent, resulting in a
higher death rate. With the spread of the epidemic many of the animals in the
country become exposed to the disease and this is followed by the development of
immunity; a period of quiescence follows although pockets of disease still
remain. The disease may flare up again with an increase in the number of young,
susceptible animals or when an outbreak due to a different type of
foot-and-mouth disease virus occurs.
11
11.Sporadic disease occurs in countries which have periods free of
the disease; it appears when foot-and-mouth disease virus is introduced from
abroad. Countries which have a completely susceptible animal population, as well
as those which practice vaccination, may suffer from sporadic outbreaks.
Successful control eliminates the disease and a period then follows when the
country is completely free from the virus, but where control measures are not
successful, a sporadic outbreak may develop into one of epidemic
proportions.
Factors involved in the introduction and spread of
the disease
12.
Foot-and-mouth disease presents serious problems because of the highly
infectious nature of the virus and its ability to survive outside the animal
host for long periods. Many factors may contribute to the introduction and
spread of the disease and these are discussed in the following paragraphs.
(i)
Imported animals
13. The disease risks associated with the importation of live animals
have long been recognised. Most countries, including Great Britain, control
imports of livestock from abroad.
(ii) Imported fresh, chilled and frozen meat and
offal
14. Shortly after a healthy animal is slaughtered an acidity develops in
the muscles, giving rise to rigor mortis. This reaction can destroy
foot-and-mouth disease virus present in the muscle. Acid changes do not take
place in any other part of the carcase and thus, if the virus were present, it
could survive in bone marrow, lymph nodes, liver and kidney. If freezing or very
rapid chilling is carried out immediately after slaughter, the acidity and
associated rigor mortis do not develop, and in these circumstances the virus
could survive for some months in muscle as well as in the bone marrow, the offal
and those other parts already mentioned. Survival of the virus can be prolonged
if infected carcases or offal are held in a chilling temperature or a frozen
state. Its presence has been
demonstrated after about six months in bone marrow stores at 10 C and in frozen
offal for at least four to five months. There is no doubt that parts of carcases
of animals slaughtered when the virus is present, whether the animals are
showing clinical signs or not, can be a dangerous source of infection. However,
a study by the Argentine-United States Joint Commission on Foot-and-Mouth
Disease has shown that the risk of the virus being present in meat is very much
less in vaccinated animals even when they have recently been exposed to
infection because the multiplication of virus in such animals is inhibited.
15.
Meat, offal and bones from infected carcases may be used in preparing swill for
feeding to pigs. Thus swill can
constitute a serious risk if it is fed to
susceptible animals before it is sterilised. Outbreaks of disease may more often be
attributed to the removal of uncooked swill by dogs, cats, birds and vermin to
fields, yards and buildings where there are susceptible animals. Kitchen waste
stored in uncovered bins, or when carried and spilled from uncovered or
unsecured transport, presents another hazard. It is also possible that an
outbreak may occur as a result of a farm worker handling swill and then coming
into contact with susceptible animals.
16.
Bones given to farm dogs may be brought into contact with susceptible animals on
any part of the farm. Some bones are disposed of by butchers as
12
waste which may be taken to a
refuse tip. Once there, they constitute a disease risk, particularly on tips in
rural areas. Even a controlled tip
is not safe since birds can get at the bones before they are covered and can
carry small bones and fragments to fields nearby.
17. Although it is known that offal and
bones constitute a major risk, we can find only two recorded outbreaks- one in
this country and one abroadΎ attributed to
meat where foot-and-mouth disease virus was recovered from commercial carcases
associated with an outbreak. Both cases involved pork; in one it was fresh and
in the other it was frozen. We do not, however, regard our inability to acquire
further evidence of this nature as significant since it is only comparatively
recently that virological techniques have been developed that are suitable for
the extensive testing that would be necessary to examine a large consignment of
imported meat.
(iii) Bones, hooves and
horns
18. It is known that foot-and-mouth
disease virus survives for long periods in bone from infected animals and there
is a possible risk of imported bones, hooves and horns introducing the disease.
Imported manufactured products from these materials for instance bone
meal-could also constitute a risk. There is no indication that any such
materials or their products have been responsible for outbreaks of the disease
in Great Britain since 1938, that is, in the period for which detailed records
are available. This may be because the climatic conditions in the exporting
countries, the delays that occur before materials can come into contact with
animals, and the manufacturing processes are all conductive toward the
destruction of the virus.
(iv) Semen
19. It has been demonstrated
experimentally that foot-and-mouth disease virus can be present in bull semen
before the infected animal has shown clinical signs and that infected semen can
give rise to the disease in an inseminated cow. Thus semen may be a source of
infection to other animals. The practice of storing semen at low temperatures is
conducive to survival of the virus. However, the risk of introducing the virus
into a country, or of spreading the virus within a country by means of infected
semen is not considered great.
(v) Glandular
products
20. Biological substances prepared from
the glands of infected animals may be contaminated by foot-and-mouth disease
virus. The virus could be passed to susceptible animals which were being treated
with such substances. In 1938 an outbreak in Great Britain was traced to a
contaminated imported glandular products used in the treatment of a cow but
there have been no recorded cases since then in this country.
(vi) Hay, straw and other
vegetable matter
21. Hay and straw are recognised as
potentially dangerous materials. Foot-and-mouth disease virus has been shown
experimentally to survive on hay for at least 15 weeks, on bran for 20 weeks,
and on straw for 4 weeks. Outbreaks of disease in Switzerland have been ascribed
to contaminated vegetable matter; there was a remote possibility that an
outbreak in Great Britain in 1951 was due to imported bulbs with which cattle
might have had contact.
13
22. The second Pretyman
Committee Report (Cmd. 2350) attributed an outbreak to swill which contained
parings from imported vegetables. The Gowers Committee found no evidence of this
in the period 1938-1953 and outbreaks have not been so attributed subsequently.
There was general agreement among our expert witnesses that the risk of
introducing the virus into Great Britain with imported vegetable matter is
insignificant.
(vii) Hides
23. Foot-and-mouth disease virus has been shown to survive for long
periods on raw and cured hides. The experience in this country suggests that
hides are not a hazard since no origins for primary outbreaks have been
attributed to them in the period since 1954. The time taken to transport hides
to this country and the urban siting of factories probably minimize the risks.
The Nene Valley in Northamptonshirea main leather processing areahas had a very low incidence of foot-and-mouth
disease over the past thirty years.
(viii) Passenger traffic
24. Spread of foot-and-mouth disease from a primary outbreak has on a
number of occasions been attributed to the movement of people who have been in
contact with infection, and this will be dealt with fully in Part II of our Report. We also found widespread recognition of
the hazard of introducing the disease through foreign travel and by visitors
from overseas. With modern fast
travel by land, sea or air and the growing mobility of populations this risk is
increasing (see also paragraph 140).
The foot-and-mouth disease virus can be carried by people on their skin,
clothing, shoes and luggage.
Experiments have shown that the virus can survive on clothing for periods
of from eighty to a hundred days.
Tourists in rural areas, farmers and livestock buyers from foreign
countries are among those who might inadvertently carry the virus. There have been two incidents in the
past where the introduction of foot-and-mouth disease was attributed to the
movement of persons between countries.
One occurred in 1937 when workers were presumed to have carried the
disease to Yugoslavia from France.
The second was in Canada in 1952 when the virus was presumed to have been
carried to that country from Europe with an immigrants effects, possibly on his
working overalls or in a meat product.
We do not consider this risk to be great; a number of countries which
remain free of foot-and-mouth disease received many visitors from countries
where the disease is prevalent.
(ix) Vehicular traffic
25. Vehicles that have carried infected animals or have been on infected
premises can play a part in the spread of foot-and-mouth disease from a primary
outbreak. They may also carry
infected material from one country to another (see also paragraph 141). The length of time that foot-and-mouth
disease virus would remain viable on a vehicle would depend on the nature of the
infected material adhering to the vehicle and on many other factors. It has been shown experimentally that
the virus can survive at temperatures of 590 -680F for two
to three days in blood dried on iron, for at least two weeks on wool and four
weeks on cow hair.
14
(x) Wind
26. The possibility that foot-and-mouth
disease virus might be transmitted by the wind has been recognized for a long
time. The Gowers Committee were
able to point out that the virus could be carried through the air for short
distances. They also reported that
the veterinarians in Scandinavia were convinced that this was the commonest way
in which infection reached their countries. Danish experience supported the theory
of windborne infection, and there was an absence of other plausible explanations
for the manner in which the virus has spread to Scandinavian countries from
Germany.
27. Since 1954 there has been further
evidence in support of the theory that foot-and-mouth disease virus is
transmitted in air currents. Recent
evidence from Denmark suggests that the virus can be windborne for up to
eighteen miles over the sea and, in exceptional circumstances, over twice that
distance. Danish veterinary
officials thought that windborne infection, associated with darkness and damp
weather, was the most frequent cause of primary outbreaks in Denmark.
28. In Great Britain much work has been
done by the Metereological Office and the Ministry of Agriculture to examine the
general hypothesis that meteorological conditions could have favoured the spread
of the virus from Continental sources on the occasion of past outbreaks of the
disease in Great Britain, and to assess the effects of meteorological conditions
on secondary spread in this country.
An examination by the Meteorological Office of all primary outbreaks
since 1937, except the minor ones, has shown that in every case of multiple and
simultaneous outbreaks on the south and east coasts, suitable wind tracks could
be found leading back to known infected areas in Europe. It was noted that in the area of the
outbreaks, rain, which could have precipitated the virus, occurred at the
relevant time. An alternative
interpretation by the Microbiological Research Establishment was that the
outbreaks could be better accounted for by the favourable effects on the
viability of the virus of the high relative humidity prevailing at the time.
29. The Meteorological Office also
examined the effect of meteorological
conditions on secondary outbreaks of the disease. This was done in five areas: Cheshire
(1952); Shropshire (1961); Northumberland (1966); Hampshire (1967); and Cheshire
(1967). (The last of these studies
had advanced to the point of examining those outbreaks during the initial stages
of the epidemic for which there were very few possible authenticated sources;
further work is in progress.)
The results of the examination suggested that wind and rain might have
played a part in the spread of the disease. In general the examination showed
that-
(i)
few outbreaks occurred upwind of a known source;
(ii)
outbreaks were limited to about 2 1/2 miles downwind in dry weather;
(iii)
outbreaks extended further down wind in wet weather and even further in
periods of light rain;
(iv)
Most outbreaks were downwind of more than one possible source of
infection on several occasions during rainy periods;
(v)
selecting the most likely sources of infection, the percentages of total
outbreaks downwind, in relation to distance, were as follows-
33 per cent within 1 Ό miles
60 per cent within 3 miles
15
75 per cent within 6 miles
85
per cent within 12 1/2 miles
90 per cent within 18 1/2
miles
95 per cent within 31 miles
(these percentage did
not include the Cheshire 1967 epidemic);
One case might have
been associated with airborne spread of the virus at a
distance of 50
miles;
(vi) in all five
areas there was a number of secondary outbreaks during the
second
week following the primary infection; after dry weather the number
was low and after wet
weather it was high;
(vii)
in all five areas there was a decline in the
number of new outbreaks
during
a period of dry weather.
The Meteorological
Office concluded that the amount of spread due to meteoro- logical causes could be as high as 95
per cent and was unlikely to be less than 80 per cent. They also concluded that
spread did not occur unless favourable wind and rain conditions prevailed.
30. The evidence suggests
that viruses contained in airborne particles will travel in a viable form in the
air for distances of up to thirty miles or more depending on the particle size,
the strength of the wind and other factors. Theory and experience
suggest that the relevant range of suitable particle size is from 2 to 10 thousandths
of a millimeter (2 to 10 microns).
The degree of upward mixing of particles depends on meteorological and
topographical factors. Transmission of airborne virus might appears to be a
greater threat than by day because of the absence of ultra-violet light. The
Microbiological Research Establishment suggested that there may be other
influences at work in the survival of foot-and-mouth disease virus about which
conclusive answers are not at present available. For example, some viruses are known to
survive better in
association with large particles rather than small ones. Atmospheric relative
humidity is a very important factor; high relative humidity appears to prolong
the survival of viruses in aerosols.
The salt and protein content of the material in which viruses are
conveyed and the extent of atmospheric pollution might exert an influence on
survival. Although heavy rain
may aid deposition of
viruses, experiments suggest that it may clear the atmosphere of noxious
substances deleterious to the viruses and so prolong their
survival.
31. The release of
foot-and-mouth disease virus into the air may be brought about in many ways.
Present work at the Animal Virus Research Institute on the presence of the virus
in the air of animal houses containing infected animals shows that the amount of
excreted virus is fairly uniform, starting before the vesicles appear and
continuing thereafter. Movement of infected animals or the disturbance of
infected materials could create an aerosol containing the virus. Animals either
housed or at pasture can be infected by inhalation of airborne virus. It has
been suggested that the virus may be drawn up into the air and carried to other
sites in thermal air currents generated when infected carcases are burned. In
this case the virus source might not be confined to the carcases; contaminated
dust particles from the ground surrounding the pyre might also be drawn up into
the air and carried away by the wind. During the 1967/1968 epidemic in the west
Midlands large volumes of air were sampled at points 100 and 300 yards downwind
from fires used to destroy
16
THE
FOLLOWING SIX COLOUR PHOTOGRAPHS
SHOW TYPICAL CLINICAL SIGNS PRESENT
IN
ANIMALS AFFECTED WITH
FOOT-AND-MOUTH
DISEASE.
17
This
proves a ruptured blister on the top of a steers tongue , and shows the ragged apperance of the
broken skin ; two pieces of skin have been removed and laid on the
animals upper lip. There is extensive seperation of the skin from the
tissue beneath and the typical raw base of the ruptured blister is clearly
visible.
18
19
20
21
This
pigs foot shows blisters as blanched areas at the junction of horn and
skin on the heels of the main difits and extending some distance up the
back of the accessory digits. The blister on the left main digit has
ruptured and lost some of its skin at its outer edge to reveal the raw
base. On the left accessory digit the skin has been lost in two places
following rupture of the
blister. |
22
This
shows blisters on the snout and tongue of a pig. There is an unruptured blister
on the right side of the snout. At the front of the tongue there is a ruptured
blister showing the raw base with the area of blanched and separated skin at
its edges; further back there is a smaller unruptured blister with its blanched
skin
.
23
carcases on two farms. No virus was isolated from the
samples but it was thought that the efficiency of the technique employed might
not have been high enough to give significant results.
32. Airborne
particles can be deposited from the atmosphere by gravity, by downward diffusion
of air, by impaction on a solid object or in a falling rain- drop. Large
particles (greater than 10 microns) will be deposited close to the source of
infection. Virus deposited on pasture or fodder can cause infection when
ingested. Smaller particles, on the other hand, will travel in an aerosol and be
little affected by gravity or rainfall (other than very heavy rainfall). The probability of infection by
inhalation will depend on the concentration of virus-containing particles in the
air. It will also depend on the viability of the virus which will be influenced
by a number of factors, the most important probably being relative
humidity.
33. It has
been suggested that animals at free range are exposed to a greater risk from
windborne foot-and-mouth disease virus than animals that are housed. On the
other hand if buildings are close to a source of infection they may act as a
trap for windborne virus, and animals inside may then be at a greater risk than
when they are outside.
(xi) Birds
34. It is
possible that birds are responsible for the introduction of foot-and-mouth
disease into countries and for its subsequent spread. It is known that the
foot-and-mouth disease virus can be conveyed on the feet or feathers of birds
and can be excreted by them after ingestion of material contaminated with the
virus, but there is no evidence that birds can become infected with the virus.
The Gowers Committee pointed out that the virus had been recovered from the feet
and feathers of a bird contaminated experimentally as long as 91 hours after
contamination. Also it was reported that starlings given the virus by mouth had
excreted it in their faces for a period of 10-26 hours. It is thus probable that birds may
spread the virus and so cause secondary outbreaks. They are likely to constitute
a greater risk if they are carrion eaters such as crows and seagulls. In the recent past there has been
considerable misgiving about attributing primary outbreaks to bird migration and
it has been suggested that many of the outbreaks so attributed may have been due
to windborne virus. Recent Danish evidence suggests that some of the outbreaks
previously presumed to have been associated with bird migration to that country
cannot be related to migration patterns.
(xii) Milk and milk products
35.
Foot-and-mouth disease virus may be present in milk from infected cows a few
days before clinical signs appear and may persist for a long time afterwards;
milk containing the virus could therefore leave a farm before disease was even
Thus milk presents a major potential hazard in transmission of the disease not
only by direct transference but also through the contamination of persons,
containers and vehicles (see also paragraph 95).
36.
Foot-and-mouth disease virus present in milk can be destroyed by varying
combinations of time and temperature; an increase in the acidity associated with
souring of milk increases the rate of viral destruction. The pasteurisation
process used for the treatment of liquid milk may be inadequate to destroy
25
the virus completely; the virus may also persist in milk
for cheese making and
in skim milk for animal feeding. Thus such products, if
infected, could play a part in the spread of the virus (see also paragraph 94
and 95). Recent work has shown that the virus in milk from an infected cow is
much more difficult to destroy than virus which has been added to milk in the
course of an experi- ment.
(xiii) Domestic and wild
animals
37. Domestic and wild animals such as
dogs, cats and foxes may act as mechanical carriers of foot-and-mouth disease
virus, especially the carrion enters. The extent of the risk will depend on the
habits of the different species. Rats may be an even greater risk in
transmitting infection since they may carry the virus in their gut for long
periods. Naturally occurring disease in hedgehogs is well authenticated but the
disease producers lameness and they do not travel far when infected. On the
other hand the hibernation of hedgehogs might be the means of reviving infection
after the lapse of a considerable period of item (see Appendix II). Deer may
also become infected naturally as well as acting as mechanical carriers, but
they have not been associated with any outbreaks in Great Britain in this
century. In some countries wild ruminants and wild pigs are important as sources
of infection and in spreading the disease.
(xiv)
Insects and arthropods
38. It has been shown experimentally
that flies and ticks may transmit foot- and-mouth disease virus from infected to
susceptible animals. The virus may survive for long periods in ticks and in
their excreta.
(xv)
Watercourses and effluents
39. The extent to which streams, rivers
and effluents act in spreading foot- and-mouth disease virus is unknown but it
an survive in water for a time sufficient for it to be conveyed to neighbouring
land by a stream. This is a possible means of spread which might be further
investigated.
(xvi) Technical
developments in agriculture
40.
The pattern of the livestock industry in many countries has changed markedly
over the last ten years; in Great Britain for example there has been a reduction
in the number of dairy units and a rise in the number of dairy cattle. It was
suggested that the number of closed herds may have been declining, with the
result that herds are less self contained than they used to be. On the other
hand there are indications that the number of closed herds may not be altering
significantly; the situation is bound to vary from time to time with changing
agricultural policy. Any increasing movement of animals, and other practices
associated with intensive farming, such as dung and slurry disposal and bulk
milk collection, may well be new factors favouring the spread of foot-and-mouth
disease.
(xvii)
Excretion of the virus by infected animals
41.
An important feature of the disease in relation to its spread is the early
excretion of the virus from an infected animal before the onset of clinical
signs. Excretion for 24 to 48 hours
before the appearance of lesions has long been
26
accepted
but experiments carried out at the Animal Virus Research Institute in 1967
indicate that longer periods of viral excretion may occur. The experi- ments
were made with the 01 prototype strain of virus, British Field
Strain 1860 (BFS. 1860), isolated
from the 1967/1968 epidemic. This work showed that the virus was excreted for a
maximum of five days in cattle and sheep and ten days in pigs before the onset
of clinical signs. (The experiment is discussed in detail in paragraphs 87 to
89). This earlier excretion is not necessarily a feature associated only with
the BFS. 1860 strain; it was demonstrated by the application of new techniques
which had not been applied previously. It was pointed out by some of our
witnesses that as the evidence relating to early excretion of virus based on
laboratory findings, it might not necessarily apply to the same extent in field
conditions. However we consider that the excretion of virus can be a significant
factor in spread for at least three days before the onset of clinical signs in
cattle, and probably for a longer period in pigs.
(xviii)
Carriers
42.
A further significant feature of the foot-and-mouth disease virus is the ability
to persist in the convalescent animal, or in the immunized animal exposed to
infection without the animal showing any clinical signs of disease. Such animals
are referred to as carriers, and the virus can be isolated from them. There
would thus appear to be a theoretical risk of such animals spreading the disease
but there is little evidence that this takes place in the
field.
43.
At the time of the Report of the Gowers Committee the possibility that
vaccinated animals might undergo a mild form of the disease and become carrier
animals was recognized, although there was little information about the nature
and incidence of the so-called masked infection that would then occur. The
introduction of general vaccination policies in many countries has made it
difficult to study the carrier state in the field, and apart from experimental
evidence we have been restricted to reviewing classical observations where
carriers might have been expected to occur. An Australian incident associated
with the export of bulls from the United Kingdom in 1871/1872, which has been
quoted as an instance of carrier transmission, has recently been reviewed by Dr.
Murray Puller (Veterinary Research Institute, University of Melbourne), and he
suggests that other factors may readily have been responsible. In the U.S.A. in
1914/1915, 740 animals that had either been infected or in contact with
foot-and-mouth disease in a show yard were, after a period of isolation, placed
in contact with young susceptible cattle and pigs. These young animals remained
free of the disease even after a protracted exposure. In an extremely severe
epidemic in Denmark in 1938/1939 where some 50 per cent of all cattle were
infected, there was no sign that recovered animals subsequently played any part
in the spread of the disease. There is some evidence, however, from studies
carried out in Africa that animals which had recovered from foot-and-mouth
disease many months previously may have infected susceptible animals. Other
repeated outbreaks attributed to carriers are not sufficiently scientifically
documented for reappraisal.
44. Since 1954 further information
has been obtained on the carrier state as a result of investigations by several
groups of research workers at the Animal Virus Research Institute, on the
Continent, at the Centro Pan Americano de Febre Aftosa (Pan American
Foot-and-Mouth Disease Center) in Brazil and at
27
the
Plum Island Animal Disease Laboratory of the United States Department of Agriculture. Their
findings may be summarised as follows:
(a) both
fully susceptible and immunised cattle may become carriers
after
experimental infection;
(b) the virus can be shown to be present in
carriers in the mouth,
pharynx,
oesophagus and the tonsils (the last especially in sheep);
(c)
over a period varying from up to a few months to two years after initial
infection, the virus can be recovered from the pharynx and
oesophagus
by taking samples of mucus with the aid of an Instrument known as a
probing;
(d)
susceptible animals kept in close contact with proved carrier animals did not
develop clinical signs of the disease nor was the virus isolated from them;
(e)
there is some evidence that in a small number of cases, the virus may pass from
carrier animals to susceptible animals; this is suggested by the presence of
foot-and-mouth disease antibody in a few susceptible animals after exposure to
carriers and by one of them resisting challenge with foot-and-foot-and-mouth
disease virus;
(f)
properly inactivated vaccine, when injected into animals, does not of itself
give rise to the carrier state.
45. The consensus of opinion among
our scientific witnesses was that the danger of carrier animals had been
exaggerated and that carriers in a susceptible population did not constitute a
significant risk. (See paragraph 124 for more recent Danish experience.) In this
context we quote the European Commission for the Control of Foot-and-Mouth
Disease who have stated that
From the material that has been collected and surveyed it would seem that only
in exceptional cases are recovered animals able to transmit foot-and-mouth
disease and therefore would seem to play a very small role in the epizootiology
of the disease.
CHAPTER
III
THE WORLD
DISTRIBUTION OF
FOOT-AND-MOUTH
DISEASE
46. The report of the Gowers
Committee reviewed the distribution of foot-and-mouth
disease during the years 1929 to 1953 both at home and over- seas. Briefly the
position abroad was that the disease had never been known in New Zealand;
Australia had not had an outbreak since 1872; the U.S.A. had enjoyed freedom for
25 years and Ireland for thirteen years. Canada had experienced only one
outbreak, which occurred in 1952. in the greater part of South America,
throughout Asia, in most African countries and in most of Europe, the disease
was either endemic or sporadic with occasional epidemics.
47. The position in Australia,
Canada, Ireland, New Zealand and the U.S.A. has not altered. We do not have
complete information on the world distribu- tion of foot-and-mouth disease but a
number of countries provided us with information (see Appendix I). Table I shows
the number of outbreaks in the countries that made
returns to the Office International des Epizooties (O.I.E.) for the year 1967.
Table II shows their population of livestock that are susceptible to
foot-and-mouth disease.
TABLE I
Outbreaks
of Foot-and-Mouth Disease in Foreign Countries in
1967,
reported to
O.I.E.
|
Country |
Reported
Outbreaks |
Country |
Reported
Outbreaks |
Country |
Reported
Outbreaks |
|
Algeria ..
..
Angola ..
..
Argentina
..
Belgium ..
..
Brazil
..
..
Cambodia
..
..
Cameroon
..
Ceylon* ..
..
Columbia* ..
D
..
..
De
..
..
East
Germany ..
France .. ..
Federal
Republic
of Germany ..
Greece .. ..
|
33
38
4,634
22
116
1
42
18,465
232
30
5
66
17
3,350
58 |
Hungary
..
India
..
..
Iran
..
..
Iraq*
..
..
Italy
..
..
Jordan .. ..
Kenya .. ..
Lebanon
..
Malawi
..
..
Mozambique ..
Netherlands ..
Poland .. ..
Portugal
..
Rhodesia
..
South
Africa
..
|
4
3,438
281
72,039
211
33
174
308
2
1
196
10
520
1
8 |
South
West
Africa ..
Spain ..
..
Sudan ..
..
Syria ..
..
Tanzania ..
Thailand ..
Togo ..
..
Tunisia ..
..
Turkey ..
..
U.S.S.R.
..
U.A.R
(Egypt)*
Upper
Volta
..
Uruguay*
..
Venezuela ..
Vietnam ..
.. |
1
305
3
293
171
248
1
2
2,068
3,323
252
14
53
68
1 |
*
Reported cases.
29
TABLE II
|
Country
|
Cattle |
Sheep |
Pigs |
Goats |
Buffaloes |
|
Algeria.. .. ..
..
Angola .. .. ..
..
Argentina .. .. ..
..
Belgium .. .. ..
..
Brazil
..
..
..
..
Cambodia
.. .. ..
..
Cameroon
..
..
..
Ceylon .. .. ..
..
Colombia
.. .. ..
..
Dahomey .. .. ..
..
Denmark .. .. ..
..
East
Germany .. ..
..
France
..
..
..
..
Federal
Republic of
Germany
Greece .. .. ..
..
Hungary .. .. ..
..
India
..
..
..
..
Iran
..
..
.. ..
Iraq
..
..
..
..
Italy
..
..
..
..
Jordan
..
..
..
..
Kenya
..
..
..
..
Lebanon .. .. ..
..
Malawi .. .. ..
..
Mozambique
..
..
..
Netherlands
..
..
..
Poland
..
..
..
..
Portugal .. .. ..
..
Rhodesia .. .. ..
..
South
Africa
..
..
..
South
West Africa
..
..
Spain
..
..
..
..
Sudan
..
.. ..
..
Syria
..
..
..
..
Tanzania .. .. ..
..
Thailand .. .. ..
..
Togo
..
..
..
..
Tunisia .. .. ..
..
Turkey .. .. ..
..
U.S.S.R. .. .. ..
..
U.A.R.
(Egypt) .. .. ..
Upper
Volta
..
..
..
Uruguay .. .. ..
..
Venezuela
..
..
..
Vietnam .. .. ..
.. |
0.540
2.117
51.227
2.759
84.000
2.290
1.850
1.910
15.019
0.390
3.374
4.700
20.300
13.981
1.100
2.014
188.800
4.900
1.510
9.600
0.072
7.242
0.105
0.410
1.135
4.030
10.767
0.904
4.144
12.500
2.330
3.914
7.500
0.507
10.549
5.300
0.173
0.600
12.650
97.100
1.630
2.400
8.680
6.702
1.100
|
6.250
0.135
49.000
0.165
21.877
―
0.300
(inc.
goats)
0.034
1.710
0.460
0.112
2.050
9.055
0.810
8.980
3.270
44.410
30.000
11.250
7.900
0.987
5.375
0.289
0.083
0.099
0.529
3.321
5.029
0.554
37.900
3.760
16.647
8.660
5.400
2.666
―
0.640
3.800
32.654
138.300
1.930
1.150
21.293
0.071
―
|
0.072
0.312
3.000
2.383
59.000
1.130
0.300
0.120
1.878
0.339
8.120
8.800
9.149
19.032
0.650
6.005
5.500
0.050
―
5.450
―
0.031
―
0.140
0.127
4.295
14.233
1.492
0.122
0.898
0.020
6.823
―
―
0.021
4.300
0.235
0.002
―
50.800
―
0.130
0.259
1.931
3.473
|
2.650
0.478
5.200
0.024
13.815
―
(see
sheep)
0.630
0.400
0.570
―
0.330
1.014
0.089
3.800
―
67.200
13.000
1.800
1.225
0.759
6.400
0.430
0.483
0.457
―
―
0.521
0.903
5.394
1.595
2.448
6.854
1.405
4.372
―
0.537
0.500
21.162
5.600
0.790
2.000
―
1.237
―
|
―
―
―
―
―
0.860
―
1.100
―
―
―
―
―
―
0.038
―
56.539
0.250
0.225
―
―
―
―
―
―
―
―
―
―
―
―
―
―
0.002
―
6.900
―
0.454
1.202
―
1.650
―
―
―
0.733
|
Populations of Susceptible Livestock in the Countries listed in Table
I
(1967) (million head)
The disease was also
present in 1967 in Burundi, the Congolese Republic, Djibouti, Ghana, Israel,
Libya, Paraguay, Republic of Niger, Republic of Nigeria and Uganda,
but we do not know the total number of outbreaks. The following countries
advised O.I.E. that they had been free from the disease in 1967: Albania
Czecholovakia
Hong Kong
Rumania
Austria
Ethiopa
Lesotho
Sweden
Botswana
Finland
Malaysia
Switzerland
Bulgaria
Gaboon
Morocco
Yugoslavia
Cyprus
30
It
was also reported that the disease does not occur in Jamaica, Madagascar and the New Hebrides, and that
Japan has not had an outbreak since 1933. Map I shows the distribution of the types
of virus throughout the world since
1954. The present situation is briefly discussed in the following
paragraphs.
Africa
48.
Foot-and-mouth disease is endemic in parts of the African Continent. An important
contributory factor to the continued presence of foot-and-mouth disease virus in
African countries is the presence of wild animals. For instance when the disease
occurs in some border regions of Rhodesia it is sometimes associated with
migrations of game from Botswana in the west and from Mozambique in the
south-east. Outbreaks of the disease which originate in wild animals often
appear to have been smouldering there for some time, and indeed strains of the
virus have been found which seem to be adapted prefer- entially to particular species of game.
The veterinary authorities in some African countries, for example South Africa,
have made determined efforts to restrict the spread of the disease by fencing
off some of the game areas. Many African countries are now promoting vaccination
schemes.
South
America
49. Foot-and-mouth disease is endemic in
many areas of South America. The
Pan American Foot-and-Mouth Disease Center, which operates under the American
Health Organisation, advises on control programmes and a number of countries have embarked
on systematic vaccination campaigns. Argentina,
Brazil and Uruguay have already established extensive vaccination programmes and
a number of other countries are developing schemes. We visited Argentina, Brazil and Uruguay
and were impressed by the progress that is being made in controlling
foot-and-mouth disease in those countries. The disease situation in Argentina is
progressively improving. The Province of
Santa Cruz and the territory of Tierra del Fuego appear to be free from
foot- and-mouth disease, and if outbreaks occur they would be dealt with by the
slaughter policy. Plans are in hand for extending this policy to the
Provinces of Chubut and
Rio Negro, and a buffer zone is maintained between the Rio Negro and the Rio Colorado, in
which all cattle, sheep and pigs are vaccinated, to protect the disease-free
area to the south. We would expect that the vigorous pursuit of their policies
will lead to the gradual isolation and then the extension of disease-free areas
in all three countries.
North and Central
America
50.
The U.S.A. and Canada have been free for many years from foot-and-mouth disease;
the last outbreak in Canada was in 1952 and in U.S.A. in 1929- both outbreaks
were eradicated by slaughter. Central America has been free the disease for some
time. The Pan American Health Organisation controls the entry of all animals,
vehicles and travellers entering Panama from the South American Continent, and
there is a zone across the Darien peninsula in which there is a restriction on
movement of cattle. Most of the large Caribbean islands are free; the last
outbreaks were in Curacao in 1961 and in Guadeloupe in 1964.There was a serious
outbreaks in Mexico in 1948 which was eradicated
(see
paragraph 122); the country has been free of the disease since
1953.
31
TABLE V
Analysis by
the Ministry of
Agriculture of Sources of
Infection
in
outbreaks of Foot-and-Mouth Disease
during the 1967/1968 Epidemic
|
Attributed
to Movement
of―
Animals
..
..
..
Vehicles
..
..
..
Veterinary
Surgeons
..
..
Other persons
..
..
..
Milk
products
..
..
..
Hay
..
..
..
..
Recrudescent
outbreaks
..
..
..
..
|
1
18(a)
6
4
9(b)
1
12
|
|
Total
..
..
..
.. |
51 |
(a)―15 milk
lorries (8 milk tankers, 7
churn
collection), 2 stock lorries, 1 slurry tank.
(b)―8 skim
milk, 1 churn washings.
84. The Ministry of Agricultures
witnesses thought that compared with
previous outbreaks of
foot-and-mouth disease in recent years, the 1967/1968 epidemic showed some new
features in that the speed and extent of spread were abnormal. There was,
however, no evidence from the length of the incubation period of the disease
that the infection differed from previous ones. In cattle the period of
incubation was from two to five days, in pigs from five to eight days and in
sheep (although this was more difficult to determine precisely) from three to
seven days. There was evidence that some sheep had exhibited a greater
resistance to infection than was expected but such resistance had occurred in
outbreaks in the past, and even when severe infections did occur in sheep they
did not give rise to much local spread of the disease. Another characteristic of
the epidemic was that pigs did not seem to be readily infected; of the 113,766
pigs slaughtered only 327 showed clinical signs of disease.
85. Laboratory evidence obtained by the
Animal Virus Research Institute showed that the 01 sub-type strains
of virus (BFS. 1860) isolated from the 1967/1968 epidemic had characteristics similar to those of
other sub-type 01 strains isolated in previous
outbreaks in Great Britain. It has been established that the BFS. 1860 strain is a little more stable
under laboratory conditions than other similar strains but it was considered
that this factor did not contribute significantly to the nature of the
epidemic.
86. During the whole period of the
epidemic samples were taken from animals where a primary outbreak was suspected,
from a random number of cases in the heavily infected areas, and from clinically
doubtful cases for diagnostic purposes.
The samples were examined at the Animal Virus Research Institute for
isolation of virus and typing, and strains recovered belonged to sub-type 01. The results are shown in
Table VI. A more detailed
investigation
54
TABLE
VI
Isolation of Foot-and-Mouth Disease Virus from
Samples taken during the 1967/1968 Epidemic
|
Source |
Number
of
samples
examined
|
Number
of samples from
which
the virus was
isolated |
|
Confirmed
cases
..
Doubtful
cases
.. |
117
105 |
114
19 |
|
Total
..
..
.. |
222 |
133 |
was
also made of five samples from animals in the areas of Oswestry, Lincolnshire, Nottinghamshire,
Warwickshire and Leicestershire between 28th October, 1967 and 19th January, 1968.
All the strains of virus isolated from these samples also fell into sub-type
01 and there was no evidence of any change in sub-type during the
course of the epidemic.
87. Experiments were also made at the
Animal Virus Research Institute to relate the time of excretion of the virus by
infected animals to the develop-ment of lesions. Cattle, sheep and pigs were
infected by contact with other animals, which had been infected by injecting the
virus, and samples for isolation of the virus taken from various sites during
the development of the disease. The results of this work are summarised in Table
VII.
TABLE
VII
Isolation
of Foot-and-Mouth Disease Virus in
Relation
to Development of Lesions
|
Animals
Steers
..
..
Cows
..
..
Sheep
.. ..
Pigs
.. .. |
Number
of days
for
lesions to develop after
exposure
to
infection
5―8
6―8
8―11
7―13 |
Number
of days before
development
of lesions
When
virus was first
Isolated |
|
|
Maximum |
Mean |
|
|
5
5
5
10 |
2.5
2.7
2.5
5.0 |
|
88. In
the same experiments determinations were made of the quantity of virus isolated
from these sites. The results are shown in Table VIII.
55
TABLE
VIII
Quantity
of Foot-and-Mouth Disease Virus
Isolated
at Various Sites in Animals
|
Site
|
Maximum
number of infectious particles
per
sample or per ml. Of milk*
|
|
Pharynx ..
..
Milk
..
..
Rectum ..
..
Vagina
..
..
|
Cattle
|
Sheep |
Pigs |
|
105.5
105.2
101.8
>103.3 |
>103.5
―
101.0
>103.1 |
>103.3
―
102.6
103.0
|
* Number
of infectious particles indicated by log scale.
Thus 102 =100, 105=100,000 and so on.
89. It is
clear from the results in paragraphs 87 and 88 that considerable quantities of
foot-and-mouth disease virus could have been excreted from infected cattle and sheep for as long as
five days, and in the case of pigs for as long as ten days, before the
appearance of clinical signs. We think, however, that this is not necessarily a
unique characteristic of the BFS. 1860 strain because little work has yet been
done on strains isolated from previous outbreaks.
90. By the
second week of the epidemic, when the disease was becoming widespread, the
pattern of spread seemed to be conforming to a well-defined shape. This took the
form of a fan from an apex in the hills at Nantmarwr with the western boundary
running northwards alongside the mountains
towards Wrexham
and Chester and the eastern boundary running towards Whitchurch and Crewe. The
Cheshire Plain lay within these boundaries. In the third and fourth weeks of the
epidemic there was roughly a twofold increase in the number of outbreaks all but
24 of which were in the Cheshire Plain or the immediate surroundings. Map VI
illustrates the developing pattern of spread of the disease in the Cheshire
Plain during the first three weeks of the epidemic. This area has always had a
high concentration of livestock and part of it is the most heavily stocked dairy
country in the world. In the conditions of the outbreaks,concentration of
livestock in the Cheshire Plain undoubtedly favoured the rapid spread of the
disease. The maps at Appendix IV show how cattle densities in Great
Britain have increased over the last nine years and how closely the areas of
highest density are related to the areas which suffered the highest
concentration of outbreaks.
91. There is
a continuing tendency in Great Britain for livestock to be kept in large groups;
stocking densities are becoming heavier and there is much more communication of all sorts between
farms, including the movement of animals.
The British Veterinary Association and the Royal College of Veterinary
Surgeons thought that in some areas all the livestock should be regarded as
an integrated population in
relation to the spread of disease. This is particularly
56
57
true
in dairying areas with a high percentage of small farms and with few
natural
breaks such as arable land and woodland between them. In this respect it is
interesting to note that in the less densely stocked areas such as
Nottinghamshire, Lincolnshire and Northamptonshire there was little or no local
spread of the disease. Developments in husbandry, and in the industries
supporting agriculture such as those mentioned above, are by no means the only ones which might play a part in the
spread of the disease. Other modern practices in relation to livestock, milk
marketing, artificial insemination, and transport and deliveries to farms
contribute to the risks (see also paragraph 40).
92. The Meteorological Office
studied the meteorological factors that might have had a bearing on
the pattern of spread of the epidemic and they concluded that wind could have
played an important part in spreading infection. They thought it was significant that at
the time of the initial outbreak at Nantmawr and for the following nineteen days the
prevailing wind was from the south-west and that about 75 per cent of the first
100 outbreaks were lying to the
north and north-east of the initial outbreak. They also thought it was significant
that rain fell on seventeen of the nineteen days when winds blew consistently
from the south-west. We noted that
very few outbreaks occurred in the
opposite direction, into the wind (see Map VI). This cannot be accounted for over a ten mile range either by a
difference in concentration of holdings or of concentrations of livestock. The
evidence supports the theory that wind
carriage of the virus together with deposition by rain at night may have
been responsible for secondary outbreaks particularly during the first month of
the epidemic. The range of spread
might have been up to thirty miles depending on weather conditions but the
longer jumps of infection into Lancashire, Nottinghamshire and Warwickshire were
not thought by the Meteorological Office to be associated with windborne
spread.
93. The Ministry of Agriculture
investigated the possibility that the virus
might sometimes have been carried by thermal air currents from sites
where infected carcases were
burnt. There were three instances
in Derbyshire during December, 1967
where outbreaks occurred downwind of infected premises after an interval of from
eight to eleven days. In these
three outbreaks the carcases had been destroyed by burning, and cremation could
have been responsible for the
spread of disease. In other
outbreaks in Derbyshire where conditions appeared to favour the spread of
disease while carcases were burning, there were no subsequent related
outbreaks.
94. Another series of outbreaks
which occurred during the fourth week of
the epidemic was of significance in relation to the spread of
disease. At Spetchley in Worcestershire,
some forty miles from the nearest outbreak in the north-west
Midlands, three outbreaks occurred in pigs, and were then followed by a further 27
outbreaks, all within a radius of three miles. The three original outbreaks were
attributed by the Ministry of Agriculture to the feeding of the pigs with skim
milk from a dairy where the plant had probably been contaminated by infected
milk. In the same week outbreaks
occurred in
Gloucestershire, at Winchcombe and near Moreton-in-the-Marsh; in both instances
pigs were the first animals affected.
The source of infection was held
to be skim milk from the dairy that had been involved in the Spetchley
outbreaks. There was also an outbreak at Wolverhampton which was attributed to
skim milk from the same
dairy.
59
95. Although it is generally
accepted that infected milk can contaminate persons, containers and vehicles and
thus convey the disease to other premises, we were told by the Ministry of
Agriculture that it was extremely difficult to assess how much disease had been
transmitted in this way during the 1967/1968 epidemic. However, investigations were carried
out, in the period from November, 1967 to January, 1968, by the Animal Virus
Research Institute, in collaboration with the Central Veterinary Laboratory into
the amount of foot-and-mouth disease virus present in milk sampled from various
sources in Infected Areas. Their
findings are given in Table IX and indicate that some samples of milk contained
high concentrations of the virus.
TABLE
IX
Quantity of
Foot-and-Mouth Disease Virus in Milk from Various Sources
in
Infected Areas
|
Source |
Number
of
samples tested |
Number
of samples positive |
Number
of infectious particles per ml.*
(Average
or range) |
|
Bulk
tankers
..
..
Churns
..
..
..
Bottles
..
..
..
Farm
storage tanks
..
Cows
..
..
..
Bulk
storage tanks
..
|
3
42
1
1
3
2 |
2
18
1
1
3
0 |
102.5 to
104.0
Trace to
105.5
105.0
104.5
Trace to
102.5
― |
* Number of infectious particles
indicated by log scale.
Thus
102=100, 105=100,000 and so on.
96. There are two risks associated
with the bulk collection of milk as distinct from churn collection at the farm
gate; the visits from farm to farm by the bulk milk tankers and the
possibility of releasing contaminated air from the tankers. The latter risk during transportation is
now considered not to be as great a danger as was at first thought but
precautions were taken to minimise the danger from this source and in December,
1967 suitable filters were fitted to the air exhausts on bulk milk tankers. The risk from bulk milk tanker
collection was, in the case of this epidemic, assessed as only marginally
greater than the risk associated with churn collection.
(c) Costs
97. The 1967/1968 epidemic was the most
serious experienced in Great Britain within this century. The numbers of stock slaughtered during
the period October 25th, 1967 to June 4th, 1968 were 211,825 cattle,
108,345 sheep, 113,766 pigs and 51 goats.
The agricultural industry was gravely affected and the consequential
disturbance and loss to many other interests were substantial. Industries relying on agriculture for
their raw materials or for their sales were affected by the controls governing
movements in and out of Infected and Controlled Areas, and sporting, leisure and
other social activities were upset.
Among the sports most seriously affected were horse racing,
fishing, hunting,
60
football, car rallying, cross-country running,
camping, canoeing, gliding, and mountaineering. Some of those whose livings were
associated with these activities suffered considerable financial loss.
98. It is impossible to put forward a reasoned estimate of the total cost
of the epidemic to the community as a whole. This would mean attempting some
assessment of the losses caused to many organizations and persons outside the
agricultural industry; it would mean attempting to put some value on the inconvenience and
mental strain caused to many individuals both in agriculture and generally, not
only by the necessity of slaughtering
a vast number of animals but also by living and working under the
unpleasant and restrictive conditions which were imposed during the
epidemic. We feel, therefore, that
it is reasonable to attempt to assess only the cost relating to the agricultural
sector of the economy, to industries and services ancillary to agriculture, to
the public sector and to consumers.
These costs can usefully be divided into direct costs and indirect
costs.
99. The direct cost of the 1967/1968 epidemic is estimated at £35.1
million largely made up of costs borne by the Ministry of Agriculture. The main item in this total is the cost
of compensation which is provisionally estimated at £26.66 million. Another large item consists of payments
for valuing, slaughtering and burying or cremating animals, and for
disinfection; these amounted to some £4.2 million. Another major item is the additional
staff costs incurred by the Ministry of Agriculture which amounted to some £2.8
million. Other direct costs are
included in the total, such as special ploughing grant payments and the £ for £
extra compensation scheme.
100. The indirect costs might be divided into two groups. The first group would cover the loss of
income arising from the slaughter of diseased animals and animals that had been
in contact with them, for though the farmer is fully compensated for the
slaughter of his stock his is still involved in losses. Com-pensation represents the capital
value of the farmers slaughtered herd which enables him in due time to replace
his stock-assuming there has been no upward movement in prices. The operation of the various control
measures, however, normally introduces a delay between the time of slaughter and
of replacing stock, and because of this and other factors the farmer loses
income for which no cash compensation is made. The next group would include costs
arising from the general disruption of agricultural production, marketing, and
distribution following the imposition of control measures. For long periods during the 1967/1968
epidemic movements of stock were substantially restricted. In particular, the normal pattern of
store stock production and marketing was seriously disrupted; from 24th
November, 1967 to 31st January, 1968 for example, the whole of Great Britain was
a Controlled Area and livestock markets were closed throughout the country.
101. Some of the indirect costs could be quantified if basic assumptions
were adopted, but there is scope for a wide divergence of views in relation to
these. Different sets of
assumptions would result in considerable differences in the calculations and we
considered that the limitations were such that it would require extensive
research. However, in a prolonged
outbreak the indirect
61
costs
are likely to be proportionately greater.
Such estimates as we received of direct and indirect costs ranged from
£70 million up to £150 million. The
estimates in the lower half of this range were the result of extensive
studies. A point of some
significance is that part of the indirect costs were borne by farmers who did
not have the disease on their farms; we received evidence that a substantial
number of such farmers had suffered heavy losses. A number of specific cases are discussed
in a valuable study carried out by
Professor W. J. Thomas and Mr. J. Stewart, of the Manchester University
Department of Agricultural Economics.
The authors mention, for example, the case of two farmers who normally
fattened store pigs and who lost several weeks output because they could not
purchase such animals. Moreover
they also had to keep on fat pigs beyond the optimum marketable weight thus
incurring a loss of about £1 per pig.
In one case the loss of income over the previous year was £430 and in the
other £200. They also mention the
case of six dairy farmers (for whom they had financial accounts) who incurred
losses estimated to range from £5 per cow (or £4 per acre) to £20 per cow (or
£10 per acre) because of the delay in getting cows and heifers into calf,
because they could not get rid of cows which they would normally have culled, or
because they incurred additional expenses on fodder to keep their animals
indoors. None of these farmers
qualified for compensation payments.
CHAPTER
VI
PREVENTION AND
CONTROL OF
FOOT-AND-MOUTH
DISEASE
(a) Outside Great Britain
102.
At one time some countries where foot-and-mouth disease was endemic accepted
that they would experience recurring outbreaks of the disease , and steps were
taken when an outbreak occurred to expedite its spread throughout flocks and
herds so that the epidemic would be terminated as soon as possible. This attitude to the disease has
disappeared except in the most backward areas. In other countries isolation of the
affected animals has been practiced but this has usually been unsuccessful
because of the highly infectious nature of the disease. These measures are still accepted by
nomadic peoples whose husbandry is dictated by climatic conditions. In those tropical countries where wild
animals share pasture with other livestock it may be necessary to accept
recurring attacks of the disease although in some African countries measures are
being taken to separate the wild from the domestic animals by stock-proof
fences. In many such areas
vaccination is now applied.
103. Control of foot-and-mouth
disease as now practiced by many countries can be considered under two main
headings: first the methods of preventing the introduction of the disease into a
country with particular attention to the importation of meat from countries
where the disease is endemic: second the methods of controlling the spread of
the disease when it is present in a country either in endemic or sporadic
form.
Control of imports
104.
The best method of reducing the incidence of foot-and-mouth disease is by
controlling imports of materials which may be contaminated by the virus. Most countries have legislation to
control such imports.
Slaughter
policy
105.
The slaughter policy is only acceptable to countries or areas of countries where
foot-and-mouth disease is not endemic and where introductions of the disease are
relatively infrequent. It may be
applied alone or in conjunction with a vaccination scheme (see paragraphs 119
and 123). The slaughter policy alone would be applied for example in Australia,
Canada, Ireland, New Zealand and the U.S.A.. The success of the policy depends on
adequate veterinary resources, the co-operation of farmers in quickly reporting
the disease when outbreaks occur, and rigid enforcement of movement restrictions
and disinfection. It also depends
on eliminating the sources of foot-and-mouth disease virus by rapid slaughter
and disposal of carcases, tracing animals that have been in contact with
infected animals, and restricting the movement of persons and animals in the
area of the outbreak. In most
countries there is legislation to provide for these procedures.
63
106.
When foot-and-mouth disease is diagnosed the infected animals are destroyed and
the carcases disposed of as quickly as possible. Steps are taken to eliminate the risk of
animals that have been in contact with the infected animals spreading the
disease. In some countries the
carcases of slaughtered animals are disposed of by burying or burning on the
farm and in others by removing animalsΎalive
or deadΎin
specially constructed vehicles to destructor plants. Sometimes the carcases are sterilised
and processed for manufacturing purposes, but they may be salvaged for human
consumption if they are apparently healthy.
General Vaccination
107. There
have been significant advances in the production of foot-and-mouth disease
vaccines and their application in the field over the last fifteen years. There are two forms of vaccine: (i)
inactivated vaccine and (ii) live attenuated vaccine. Inactivated vaccine is ideal for use in
countries wherefoot-and-mouth disease is endemic. Great improvements have been
made in the preparation of potent inactivated vaccines and these are used in
most countries which have adopted vaccination policies. In some centers of research, including
the Animal Virus Research Institute, much effort has been directed in the past
ten years towards developing live attenuated foot-and-mouth disease
vaccine. However, the highest
standards of safety and potency have not been attained and the application of
this type of vaccine is limited to a few areas. Its successful use reduces the frequency
and extent of epidemics and it has been used as a preliminary to a more
comprehensive scheme of vaccination with inactivated vaccine.
108.
Of those countries that have replied to our questionnaire the following
incorporate general vaccination in their control programmes:
Argentina
France
Kenya
Belgium
Federal Republic of
Netherlands
Botswana
Germany
Switzerland
Brazil Italy
Uruguay
109.
The types and sub-types of foot-and-mouth disease virus that give rise to the
disease in a particular area are usually predictable, and countries that
practise vaccination use vaccines containing the virus types and sub-types
appropriate for their areas. (The
vaccines are referred to as monovalent, bivalent, trivalent or polyvalent
depending on the number of different virus types they contain.) In Argentina, Brazil, France, the
Federal Republic of Germany, the Netherlands, Switzerland and Uruguay cattle are
vaccinated with trivalent vaccines which contain sub-types of three main types
of virus. The sub-types may be
varied from time to time. In 1968
the sub-types in use were
Argentina:
A24
: 01 :
C3
Brazil
A24 : 01 :
C3
France
A*
: 01 :
C1
Netherlands
A10 : 01 :
C1
Federal Republic
of
Germany
A5
: 01 :
C1
Switzerland
A5
: 01 :
C1
Uruguay
A5
: 01 :
C3
*At
present being classified for sub-type by World Reference Laboratory,
Pirbright.
64
110. Some strains of foot-and-mouth
disease virus have a wide antigenic spectrum and when incorporated into vaccines
give a broad measure of protec- tion against a number of sub-types. It has also been shown that animals that
have been subjected to routine vaccination on a number of occasions will be
better protected against a range of sub-types than those that have received
vaccine on only one or two occasions.
General vaccination may therefore give some protection against a sub-type
which is introduced into an area for the first time. This may not always be the case and if a
new sub-type has to be incorporated in vaccine which has to be manufactured a
minimum period of two months, to allow for carrying out efficacy and safety
tests, is usually required before the vaccine is ready for use. However, world monitoring services (see
also paragraph 120) should allow sufficient notice to be given of the spread of
new sub-types and thus allow their early incorporation in the vaccine. In an emergency, for example in the face
of a rapidly spreading epidemic, vaccines that had passed the safety tests could
be used without waiting for the results of efficacy tests and so reduce the
waiting period considerably. The
same procedure could apply if a new
virus type had to be incorporated in the vaccine.
111. The results of experiments at the
Animal Virus Research Institute given in the Figure IV overleaf show the
antibody production (which is related to protection) in cattle following a
single injection of vaccine in which aluminium hydroxide is used as an
adjuvant. In animals not previously
vaccinated (line B) antibody is produced by the fourth or the fifth day, and by
the sixth day is sufficient to resist an average challenge of foot-and-mouth
disease virus. It is considered
that by the seventh day, 85 per cent of vaccinated cattle would have achieved a
sufficient level of antibody (1.5 on the scale used) to be immune to the
disease. In cattle that had been
vaccinated previously there is a greater and more rapid antibody response (line
A). Antibody to a particular
sub-type of virus is also produced even when the sub-type used in the vaccine
originates from a different strain (line C), but the response is not so rapid
and it does not reach as high a level.
In all three immunisation procedures (A, B and C) after about a month
there is a gradual fall in antibody level and by the fifth or sixth month it may
be undetectable. A similar response
to foot-and-mouth disease vaccine occurs in sheep but in pigs it is much less
satisfactory.
112. Work on oil adjuvant
foot-and-mouth disease vaccines has shown promise and has already reached the
stage of field trials. These
vaccines are likely to give a reasonable degree of protection within three or
four days of vaccination, to prolong the period of immunity and to be almost as
effective in pigs as in cattle. Oil
adjuvant vaccines that are available at present may produce a tissue reaction
around the site of the injection, particularly in pigs, but there is reasonable
promise that this drawback will be overcome.
113. Primary outbreaks often occur
in pigs and thus theoretically there is an excellent case for vaccinating
them. But because of the rapid
turnover of the pig population and because hitherto there has been no really
satisfactory vaccine for pigs, general vaccination of this species is not
usually practiced. It is known that in countries with a vaccinated cattle
population the disease sometimes remains undetected in pigs for a period and is
only revealed when young unvaccinated susceptible cattle are exposed to
infection. These animals are described as indicators or revealers because
they show the presence of latent disease. Furthermore, sheep may be very
resistant to disease and there is
65
FIGURE IV
NEUTRALISING ANTIBODY*
RESPONSE OF CATTLE TO
INACTIVATED FOOT-AND-MOUTH
DISEASE VACCINE
Antibody level is given as
LOG10 of the geometric mean titres
of a number of sera.
The broken line indicates the
level at which protection may be expected.
*Neutralising antibody gives
an indication of protection.
0 Heterologous vaccine is
prepared from a different but closely related
strain from the one used to measure the
antibody.
Source:-
Miinistry of Agriculture
66
a danger that they may
harbour the virus for long periods; its presence would only become apparent when
they come into contact with, and transmit the virus to, susceptible animals.
114. Young animals of all species
can absorb antibodies from immune dams through colostrums (the first milk) in
the first 24 to 36 hours of life.
These maternal antibodies may confer protection, which varies from a few
weeks to a few months, after which the young animals become completely
susceptible. Maternal antibodies
inhibit the response to vaccination and for this reason, in countries with
general vaccination programmes, young animals are usually not vaccinated until
they reach the age of four to six months when maternal immunity is lost. In the Federal Republic of Germany,
however, calves aged two months are vaccinated on the assumption that either the
animal is already protected by maternal antibodies, in which case the vaccine
will not induce more protection, or that the animal is not immune and will
respond satisfactorily with the development of antibodies.
115. In order to be successful a
general vaccination scheme need not necessarily cover the entire susceptible
livestock population of a country.
A scheme covering a high proportion of the population, although not
ensuring that every animal is immune, nevertheless builds up a national herd
immunity which limits the number of primary outbreaks of foot-and-mouth disease
and which breaks the chain of transmission of the virus, thereby also limiting
the number of secondary outbreaks.
In those countries in Europe where general vaccination has been adopted
it is usual to protect only cattle.
116. The schedule of doses of
foot-and-mouth disease vaccine varies in different countries. In France where animals are vaccinated
only once a year, the operation is spread over the whole year so that the entire
cattle population is never wholly susceptible. In the Netherlands vaccination takes
place in the Spring, but any young animals that have attained the age of four
months are vaccinated in the Autumn; other young animals are vaccinated as they
are moved off the farm. In
Argentina cattle are vaccinated three times a year and from the beginning of
1969 sheep are being included in the vaccination scheme.
117. In European countries vaccine
is administered by veterinarians but in other countries, for example Argentina,
the veterinary corps is insufficient in numbers to make this policy practicable
and vaccination is supervised by local livestock committees which have farming
and veterinary members.
118. The burden of cost of
vaccination is spread in various
ways but in general the farmer pays, either directly or through marketing or
co-operative associations, in part or in whole. Where general vaccination is practiced
farmers appear to be satisfied that it constitutes a good insurance against the
risk of infection and the consequential disturbance, loss of profits and, in
some cases, of valuable livestock.
119. Many European countries
employing general vaccination also employ a slaughter policy. Outbreaks of foot-and-mouth disease are
dealt with by slaughtering the infected animals and sometimes those that have
been in contact with them. These countries may also apply ring
vaccination round the area of an outbreak, over a distance of from one to three
miles. (See paragraph 123). These additional measuresΎslaughter
and ring vaccinationΎ
have contributed
67
considerably to the success
of general vaccination campaigns and may now be largely responsible for
maintaining the improved situation.
The vaccination campaigns in Belgium, France, the Federal Republic of
Germany, the Netherlands and Switzerland have undoubtedly been successful,
although these countries still have an epidemiological problem among their large
susceptible pig population (see Table III).
Barrier
Vaccination
120. Barrier vaccination involves
the vaccination of all susceptible animals in a buffer zone to prevent
foot-and-mouth disease spreading from one area to another. The successful application of barrier
vaccination depends on the knowledge of the distribution and movement of the
types and sub-types of the virus.
The international agencies which help in this task are the Office
International des Epizooties, (O.I.E.), the Pan American Foot-and-Mouth Disease
Center, the European Foot-and-Mouth Disease Commission of the Food and
Agricultural Organisation of the United Nations (F.A.O.), the Near East Animal
Health Institute at Beirut (also part of F.A.O.) and the Inter-African Bureau
for Animal Health. The Animal Virus
Research Institute also assists in this work in its role as the international
reference laboratory and is designated by F.A.O. as the World Reference Centre
for typing and sub-typing of strains of foot-and-mouth disease virus. An example of barrier vaccination is to
be found in Argentina, which maintains a buffer vaccination zone running
east-west across the whole country to protect the provinces south of the Rio
Negro; Denmark also uses barrier vaccination along its southern borders when
there is a threat of the introduction of disease from northern Germany. Such vaccination may be carried out
either with a monovalent vaccine if the type of virus is known, or otherwise
with a polyvalent vaccine.
121. Barrier vaccination was
successfully practiced when, from 1962 onwards, south-east Europe was threatened
with the introduction of the type SAT 1 virus which had not previously occurred
on the Continent. Vaccination
measures, co-ordinated by the European Economic Community, the Office
International des Epizooties and the Food and Agriculture Organisation, were
introduced to prevent the spread of the disease. In November, 1964 the disease situation
on the south-eastern borders of Europe was further complicated by the emergence
of the sub-type A22 virus which spread rapidly from east to west
through the whole peninsula of Anatolia and reached Greece. Investigations showed that only the
homologous sub-type A22 vaccine would prevent further spread into
Europe. Supplies of such vaccine
were produced for use in buffer zones in Bulgaria, Greece and Turkey. In addition a vaccination campaign with
sub-type A22 vaccine was
carried out in parts of Turkey.
Many European countries contributed financially and by seconding staff;
the United Kingdom Government supplied approximately £550,000 in cash and in
vaccine. The measures taken
successfully prevented the further invasion of Europe by type SAT 1 and sub-type
A22 viruses.
122. In Mexico a rather different
form of barrier vaccination contributed to the control of a foot-and-mouth
disease epidemic which started at the end of 1946. Early efforts to control the disease by
a slaughter policy met with only limited success and a vaccination policy was
introduced in large quarantine
68
zones which were established by starting barriers fifty
miles from known outbreaks and moving towards the source of infection. Eradication of the disease was
accomplished by August, 1951.
Ring Vaccination
123.
Control of foot-and-mouth disease by ring vaccination may be carried out in a
country with a completely susceptible livestock population. It involves the vaccination of all
susceptible animals in a prescribed area around an out-break and depends for its
success on the rapidity by which diagnosis, typing the virus and vaccination are
carried out. If a suitable
monovalent vaccine is available, consisting of the type or sub-type similar to
that of the virus responsible for the outbreak, it would probably be used on
these occasions; failing this a trivalent vaccine, if it contained the
appropriate type of virus, might be used.
Vaccination may be carried out in conjunction with slaughter of the
infected animals and those that have been in contact with them.
124.
Ring vaccination is practised in DenmarkΎa
country which does not import carcase meat and which is not subject to many
primary outbreaks. All
cloven-hoofed animals on the affected farm are slaughtered unless they are
judged to be immune as a result of previous vaccination. Cattle and sheep (but not pigs) within a
perimeter of at least six miles are vaccinated and this is usually completed by
local veterinary surgeons within ten days of the outbreak. Animals in the vaccinated area are
retained within this area for some time; in the past this was usually several
months but now the policy is that these animals may move out after thirty
days. Restocking of cattle is
permitted after disinfection of the farm on condition that the new stock have
been vaccinated against the actual type of virus responsible for the outbreak at
least three weeks and not more than two months before they are moved on to the
farm. Restocking of pigs can take
place six weeks after disinfection.
Calves born on the farm have to be vaccinated at an age of three to four
weeks, and the vaccination is repeated every fourth month for twelve
months. There is a general rule
that for five months after ring vaccination, cattle and sheep moving into the
vaccinated area must have been vaccinated at the same time as, or after, the
ring vaccination; however this rule may be waived. Some of the animals when vaccinated
could be in the early incubation period of foot-and-mouth disease and a small
proportion of them could become carriers of the virus. However, the prompt slaughter of the
affected animals at an early stage before much virus is shed may mean that the
carrier state arises in very few, if any, animals. The importance of the Danish experience
is that no problem has arisen as a result of releasing cattle from within
vaccinated areas and allowing them to mix with susceptible animals in other
parts of Denmark.
(b) In Great Britain
Measures
to control the introduction of foot-and-mouth disease virus
125.
Precautionary measures to limit the introduction of foot-and-mouth disease into
Great Britain are provided for in legislation or in agreements, as set out in
Appendices V and VII. Orders are in
force covering:
imported livestock;
Imported meat and meat products;
69
Imported meat wrapping materials;
imported hay, straw and grass;
imported semen;
imported sera and glandular products;
vehicles carrying livestock.
These control measures appear to have been generally
effective except in regard to meat imports to which the Ministry of Agriculture
have attributed the majority of foot-and-mouth disease outbreaks. We will
therefore deal with this aspect in some detail.
126. The countries from which Great
Britain imports meat fall into four
categories:-
(i)
countries free from foot-and-mouth disease, for example Australia
and New Zealand, to which no restrictions are applied;
(ii) countries where the disease is
sporadic and slaughter is included in the control policy, for
example Denmark, France, the Netherlands and
Poland. The conditions which
are applied to such countries include the requirement that the origin of the
animals and the place of slaughter shall be at least 20 kilometers (about
12½ miles)
from any known outbreak of foot-and-mouth disease that has occurred within the
last 28 days. A sudden upsurge in
the number of outbreaks of the disease or a tendency for the disease to break
out from controlled areas would call for immediate consideration of a general
ban on imports from the country concerned.
Imports are suspended when in the view of the veterinary authorities in
Great Britain there is a risk of temporary loss of control over the disease;
(iii) countries or areas of
countries in which the disease is sporadic and in which a slaughter policy is
not normally practised but where movement control measures are adopted, for
example South Africa. Conditions
are imposed requiring certification that the origin of the animals is from
regions which have been free from foot-and-mouth disease for at least six
months;
(iv) countries where the disease
is endemic and where the Bledisloe arrangements apply; these are Argentina,
Brazil, Chile and Uruguay. (See
Appendices VI and VII).
127.
The Bledisloe arrangements were first introduced in 1928 and the four countries
to which they apply, particularly Argentina and Uruguay, have exported large
quantities of meat to Great Britain for a very long time. Under these arrangements these countries
are permitted to export meat to Great Britain under less stringent animal health
conditions than those which apply to other countries from which we import
meat. The original Bledisloe
arrangements (Appendix VI) were revised in October, 1968 (Appendix VII)
following a visit to all four countries by a British veterinary mission. The revised arrangements require that
only carcases from animals that have been properly vaccinated against
foot-and-mouth disease shall be exported to Great Britain. Such animals are unlikely to develop
infection if exposed to foot-and-mouth disease virus, or to harbour it, and
therefore these revised arrangements will undoubtedly reduce the risk from meat
imports.
70
128. Other additional disease
precautions in regard to meat imports from these four countries have been
introduced from time to time in the light of experience. In 1961 imports of pigment and pig offal
were prohibited; this ban is still in force. In December, 1967Ύat
the height of the 1967/1968 epidemicΎa
complete ban was imposed on the importance of South American meat and
offal. On 15th April, 1968 the ban
was removed from carcase beef and beef offal but was retained on imports of
mutton and lamb including their offal.
129. The complete ban, imposed in
December, 1967, was simultaneously applied to all other countries exporting meat
to Great Britain with the exception of Australia, Canada, Finland, Iceland, New
Zealand, Norway, the Republic of Ireland and the United States of America. As with the South American countries,
the ban was removed on 15th April, 1968.
Control
of outbreaks
130. Great Britain has relied on
the slaughter policy for controlling foot-and-mouth disease since 1892 when an
Act was passed authorizing the Board of Agriculture to carry out compulsory
slaughter. A serious epidemic
occurred in 1922 and although the slaughter policy was generally applied, some
of the affected herds were isolated where the circumstances were such as to
provide what were then considered adequate safeguards against the spread of the
disease. Isolation was abandoned in
1925 and since then the slaughter policy has been rigidly applied. This has been the means of reducing
spread to the susceptible livestock population of Great Britain which in June,
1968 numbered about 44 million, including approximately 11 million cattle, 27
million sheep and 6 million pigs.
In the following paragraphs we give a brief description of the slaughter
policy as it applies in this country at present; there are many administrative
arrangements involved and we shall return to these in part II of our
Report.
131. As soon as a suspected case
of foot-and-mouth disease is reported the Ministry of Agriculture serves a
notice on the farmer which prohibits movement on or off his farm except under
the permit of the Ministrys veterinary inspector. The inspector then examines the animals
and if necessary he arranges for specimens from them to the tested at the Animal
Virus Research Institute. He may
impose restrictions on an area of five miles radius of the suspected outbreak
which prohibits movement of all animals within that area except under
licence. If the case is confirmed,
an Infected Area of approximately ten miles radius is immediately declared. The actual extent and perimeter of an
Infected Area varies depending on the physical or legal boundaries by which it
can be defined and the availability of slaughtering facilities. No movements of animal may take place
within an Infected Area except under licence; such licences are issued either
for direct movement to a farm (where the animals must remain for fourteen days
without further movement) or from a farm to a slaughterhouse, or to a fatstock
market for slaughter within the area.
The Infected Area Order imposes other conditions relating to the movement
of certain classes of persons, animals and materials within an Infected
Area. No licenses may be issued for
movement of animals out of an Infected Area.
71
132. Where there might have been widespread dissemination of the
disease, such as through a market
or a dealers premises, it may be necessary to impose wider restrictions, that is
Controlled Area restrictions, which prohibit movements and markets without a
licence. The object of these wider restrictions is to control movements until
animals that may have been in contact with infected stock have been traced and inspected by the Ministrys
veterinary staff.
133.
Infected animals are slaughtered immediately the disease is confirmed; the
remaining animals on the farm are slaughtered after valuation. The
carcases are buried or, in certain cases where burial is not practicable,
are
burnt.
134.
Formerly the carcases of animals which had been in contact with infected animals but which were at the
time of slaughter apparently healthy were salvaged in Great Britain but this
practice had been abandoned by 1927.
Salvage was reintroduced during the second World War but it was condemned
in the Gowers Report and thereafter was no longer practised. Cases have been recorded of infected material
from salvaged carcases being introduced into swill and thus giving rise to
further outbreaks. The Gowers Committee recorded the following incident
Ύ
The
first case of the exceptionally severe epidemic in Dumfriesshire was reported on the 2nd June
[1952], in
pigs owned by a dairy company at Holywood. The next day outbreaks occurred on
two adjoining farms as well as at
Lockerbie, some ten miles away. The evidence available indicated that these three
outbreaks were either spread from the Holywood dairy or had a common origin with
the outbreak there. That
origin appeared to be meat salvaged from the outbreaks at Wigtown which was sent
via a Dumfries butcher to a school-meal kitchen at Marchmont, Dumfries. Kitchen
waste found its way to a piggery (about half a mile from the dairy companys
premises) where it was stored, unboiled, in bins in the open. Rooks abound in
the neighbourhood, and it is known that they frequently fed from these swill
bins. It is likely that they carried the infection to the dairy company, since
there also the birds feed from feeding troughs in the open. Thirty-seven
outbreaks followed in the vicinity of Dumfries.
135.
In isolated outbreaks of disease restocking of the infected farm is allowed 28 days after final disinfection
or 42 days after slaughter, whichever is the earlier; but when there has been a
number of outbreaks in close proximity these times for restocking relate to the
time of the last outbreak in the area.
It is usual to reduce the size of an Infected Area to about five miles
round the infected farm fourteen days after the last outbreak and to remove
restrictions after 21 days. Controlled Area restrictions are removed as soon as
possible in order to permit livestock trading to be resumed.
136.
Preparations for the emergency use of vaccine were made during the 1967/1968
epidemic. During the second half of November, 1967 it was decided to prepare contingency plans for
an extensive ring vaccination programme as a second line of defence. A stock of
type O1 monovalent vaccine
72
was
acquired and a plan of campaign was drawn up in the first few days of December. Some five hundred veterinary
surgeons who were not employed
in the foot-andmouth disease control programme were prepared to leave
their normal work and commence vaccination. The plan assumed that full scale
vaccination could be started within four days of a decision being taken to
vaccinate and that about two million animals could have been vaccinated in ten days. In the event, the plan was not
necessary as during December it became apparent that the epidemic was
waning.
73
CHAPTER
VII
DISCUSSION
OF FUTURE POLICIES FOR
GREAT
BRITAIN
137. There
are three main policies for dealing with the prevention and control of foot-and-mouth
disease which can be adopted either singly or in
combination:
(a) Import
policyΎdesigned
to reduce the risks of introducing the disease into the country by
restrictions on imports which may carry the virus.
(b) Slaughter
policydesigned
to isolate and stamep out outbreaks of the
disease when they occur.
(c)
Vaccination policydesigned either to limit the number of primary
outbreaks
as well as the subsequent spread (general prophylactic
vaccination), or solely to limit the spread of the
disease when primary
outbreaks occur (ring vaccination).
(a) Import
Policy
138.
There are a number of ways by which foot-and-mouth disease may be introduced
into Great Britain; they have all been referred to in previous chapters and may
be summarized as follows:
(i) wind tracks carrying airborne virus;
(ii) migratory
birds;
(iii) travellers coming from
abroad;
(iv) traffic from
abroad;
(v) importation of
semen;
(vi) importation of sera and glandular
products;
vii) importation of hay, straw and
other vegetable matter;
(viii) importation of live
animals;
(ix) importation of meat wrappings which
mayhave been exposed to
the risk of contamination by the virus;
(x) importation of meat and meat
products.
139.
The introduction of foot-and-mouth disease virus by wind and birds cannot be
controlled. However, the improved situation regarding foot-and-mouth
disease in the northern parts of
the Continent of Europe over the past few years undoubtedly has reduced the
risks from these methods of introduction and has probably been responsible for
the reduction of the number of primary outbreaks in the east and south coastal
areas of England. There are no suitable wind tracks or migrations from countries
such as Spain. All our witnesses thought that the risk of introduction from
Continental sources by wind and birds is now small.
140.
International travel for business and pleasure is increasing every year. This
trend is likely to continue. In 1957 the number of foreign visitors arriving in
this country was about 1Ό
million and by 1967 the number had increased to nearly 3½ million; over 2
million of those who landed in 1967 arrived by
74
air.
The number of British travellers abroad has also increased; in 1957 nearly 3
million of them returned to the United Kingdom and by 1967 this figure had
increased to about 6½ million. About 4 million of those who landed in 1967
arrived by air. All our witnesses acknowledged that there could be a risk of
foot-and-mouth disease transmission from country to country by travellers
although none rated it very highly. It seems that this risk may not be great but
transmission of the virus by this means would often be impossible to prove.
Although with the rising volume of travel the risk could increase, we think that
satisfactory foot-and-mouth disease control programmes overseas will certainly
reduce it. Some countries free of foot-and-mouth disease have taken elaborate
precautions, when threatened with the introduction of the disease, to inspect
passengers and baggage at the port of entry and to ensure that they pass through
a decontamination barrier, but we consider that to do this effectively would be impracticable because of
the magnitude of the problem.
141.
The risk of introducing foot-and-mouth disease arising from vehicular traffic
from abroad has also increased. This risk is greatest when animals or other
potentially dangerous materials are transported. There are Statutory Orders (see Appeindix V) dealing with this matter which
require the cleansing and disinfection of vehicles which have carried animals
before they are used to carry other
animals; these requirements, however, might not necessarily
be implemented until vehicles have travelled far inland. We consider that such
vehicles should be cleansed and disinfected at the ports of entry and that
the present facilities for doing so
are inadequate. Facilities should also be available for disinfection
of personnel who come in contact with such vehicles.
142.
The importation of semen, sera and glandular products and the importation of
hay, straw and other vegetable matter is dealt with in Great Britain by
legislation (see Appendix V).
It was considered by all our expert
witnesses that the importation of these materials under present legislation does
not constitute a serious risk of introducing foot-and-mouth disease
virus.
143.
One of the major risks of introducing foot-and-mouth disease virus into Great
Britain could be from the importation of live animals susceptible to
foot-and-mouth disease. In this respect Great Britain exercises rigid control
procedures(see Appendix V) which have apparently been successful in preventing
the introduction of the disease by this means. There has never been an outbreak
associated with animals imported under these Regulations, and our witnesses
agreed that little or no risk was involved under present
legislation.
144.
The importation of meat, meat products and meat wrappings constitutes a serious
risk particularly in relation to bones and offal (see paragraph 14). We think that the way in which offal is
treated makes the risk from this source less than the risk from bones; in
general there is little waste thrown away from offal before it is cooked. We accept
however that tainted offal might be thrown away without having been cooked and
there is also a risk from wrappings and residual blood from
offal.
145.
Great Britain imports meat and
meat
products from countries which are completely free from foot-and-mouth disease,
such as Australia and New Zealand, from countries where the disease is sporadic,
and also from countries where it is endemic. There is no risk of introducing the
disease by the importation of meat and meat products from countries which are
free from the
75
disease,
but there are differing degrees of risk when imports are from countries where
the disease is endemic or sporadic, depending on their disease
status.
146.
The quantity and type of meat and meat products imported into Great Britain from
countries where foot-and-mouth disease is sporadic are included in Appendix
VIII. Such imports carry a risk of introducing the disease and although strict
control legislation (see Appendix V) is enforced, there clearly remains a
potential risk in importing meat and meat products from countries suffering from
sporadic outbreaks. This risk would diminish as the animal health situation in
such countries improves. Effective controls must depend on the ability at short
notice to revoke licences whenever dangerous situations arise in exporting
countries. We consider it essential that the importation of meat and meat
products should be governed by a machinery which is sufficiently flexible to
cope swiftly and adequately with the many differing and often fast changing
situations which can arise in these countries. We are satisfied that the general
use of revocable conditional licences must be accepted as the only satisfactory
means of providing this essential flexibility.
147.
The figures of meat imports given in Appendix VIII also include those from
countries where the disease is endemic, namely Argentina, Brazil, Chile and
Uruguay. We consider that the risk of introducing foot-and-mouth disease into
Great Britain in respect of imports from these countries is always high. We have
explained in Chapter II that foot-and-mouth disease virus can remain viable in
various parts of an infected carcase for long periods and although the virus has
been isolated from meat responsible for an outbreak of the disease on only one
occasion in Great Britain, we are satisfied that the majority of primary
outbreaks in this country have been caused by imported meat from countries where
the disease is endemic.
148.
Table X overleaf gives the origins to which the Ministry of Agriculture
attributes the primary outbreaks of foot-and-mouth disease in the period 1954 to
September, 1967. Of the 179 primary outbreaks, 74(41 per cent) were attributed
to imported meat and meat wrappings from countries where the disease was
endemic. It may well be that some of the 40 outbreaks (22 percent of the total)
to which no origin could be attributed were also from meat sources.
149.
Great Britain has recognised for a long time the danger of importing meat from
Argentina, Brazil, Chile and Uruguay and over the years has made arrangements
and imposed certain restrictions regarding meat imports from these countries to
reduce the risks (see paragraph 127 and Appendix VI). The situation before the
1967/1968 epidemic was that beef, lamb and mutton, together with their offal,
could be imported under the Bledisloe arrangements but there was a complete ban
on the importation of pig meat and pig offal.
150.
At the height of the 1967/1968 epidemic further restrictions were simposed on
meat imports from Argentina, Brazil, Chile and Uruguay (see paragraph 128). In
April, 1968 restrictions on imports of carcase beef and offal were removed but
the bans on pigmeat and offal, and mutton and lamb and their offal, have
remained in force. Further, as a result of a veterinary mission which visited
these countries in May, 1968, the Bledisloe arrangements were revised and put
into operation in their new form in October, 1968 (see Appendix
VII).
76
TABLE
X
Origins
Attributed by the Ministry of Agriculture to
Foot-and-Mouth
Disease Outbreaks from 1954 to September, 1967
|
Year |
Primary
Outbreaks |
|
Attributed by ministry of Agriculture
to: |
|
Imported Meat
and Meat Wrappings |
Birds and other
Origins |
Origin
Obscure |
|
From countries
where the disease is: |
From
unidentified countries |
|
Endemic |
Sporadic |
|
|
|
|
|
|
|
1954
1955 ..
.
1956 ..
.
1957 ..
.
1958 ..
.
1959 ..
.
1960 ..
.
1961 ..
.
1962 ..
.
1963/1964..
1965 ..
.
1966 ..
.
1967*.. .. |
8
7
32
43
29
9
26
18
2
-
1
2
2 |
8
6
13
13
8
3
12
7
2
-
-
-
2 |
-
-
-
1
-
-
-
3
-
-
-
-
- |
-
-
4
9
2
3
1
-
-
-
-
-
-
|
-
-
10
17
13
1
1
-
-
-
-
-
- |
-
1
5
3
6
2
12
8
-
-
1
2
- |
|
Totals ..
.. |
179 |
74 |
4 |
19 |
42 |
40 |
*January to
September.
151. We have considered what additional modifications in
the import policy could be introduced in order still further to reduce the risk
of introducing foot-and-mouth disease into Great Britain. The existing policies,
except in relation to meat from countries where the disease is endemic, were
considered satisfactory. They should not however be regarded with complacency;
con-stant surveillance should be exercised to ensure that their present
effectiveness is maintained.
152.
With regard to the importation of meat from countries where the disease is
endemic the most effective policy would be a ban on chilled and frozen beef and
beef offal; this, together with existing bans on pork, mutton and lamb and their
offal, would amount to a total ban on all carcase meat and unprocessed offal
from these countries. We are impressed by the freedom which countries such as
Canada, Northern Ireland, the Republic of Ireland and the U.S.A. have had from
the disease as a result of such a policy.
153. A
number of organisations stated in evidence that a total and lasting ban on meat
imports from countries where foot-and-mouth disease is endemic would give rise
to supply problems, and so to pressure on prices, for a period of some years.
Judgements on the social, political, and commercial implications of a ban on
meat imports do not fall within our terms of reference but we feel it would be appropriate to describe the
broad pattern of United Kingdom meat supplies and meat marketing which emerges
from the evidence.
77
154.
In 1967, 28 per cent of the total United Kingdom supply of carcase meat and
offal (beef, veal, mutton, lamb and pork) was imported; this was valued at about
£162 million c.i.f. Within the total United Kingdom supply figure, the import
situation varied between different types of meat. About two per cent of the
total tonnage of pork, 23 per cent of the total tonnage of beef and veal, and 57
per cent of the total tonnage of
mutton and lamb were imported. Some 40 per cent of total offal supplies was
imported, to the value of about £22 million c.i.f..
155.
In the United Kingdom, beef production is still subject to a considerable
seasonal variation with supplies in October and November about 33 per cent
greater than in June and July. Grass-fattened cattle, marketed in the autumn,
have a cheap finishing period in contrast with the more expensive fattening of
cattle through the winter for the marketing in the Spring. In both cases,
however, the fattener derives his beef store cattle from two main
sources:
(i) store
cattle from the United Kingdom beef and dairy herds;
(ii)
the Republic of Ireland (620,000 head in 1967, of which about
200,000 entered Northern Ireland).
Physically
similar conditions and close economic integration, particularly in the meat and
livestock sector, result in the seasonal production pattern of the Republic of
Ireland following, and hence accentuating, that of the United Kingdom. Lamb production in the United Kingdom
depends even more upon the seasons than beef, with the bulk of marketings in the
second half of the year. Sheep are
marketed fat in a similar annual pattern. Pig production meets the requirements
of the market for pork and manufactured products as well as a significant share
of the bacon market; it is not subject to any natural seasonal conditions or
variations. Supplies of all poultry meats in 1967 totalled some 438,000 tons,
almost entirely home production, which has been increasing over the last few
years at the rate of about ten per cent per annum. In contrast to cattle and
sheep, home production of pigmeat could be expanded greatly and quickly because
of the short production cycle, the prolificacy of the pig and its limited direct
requirement for land. Production of poultry meats could also be greatly expanded
at comparatively short notice to
meet
demand. Thus the scope for increase
home production in the short-term would depend primarily on poultry and pigmeat.
An increase in beef, mutton and lamb would take significantly
longer.
156. Fatstock, both cattle and sheep,
are sold mainly through about 600 regular liveweight auction markets which are
approved certification centers
under the Fatstock Guarantee Scheme. There are some hundreds of other
markets which are not approved
certification centers. Some liveweight sales by private treaty take place
but in quantities of minor importance. The other major method of marketing is
sale by deadweight at a slaughterhouse of which there are over 2,000; about a
half of these are approved certification centers. Buyers include retail
butchers, wholesalers and dealers; local retail butchers may buy to cater for
local demand. More important in total are the buyers who are catering for the large
urban demands throughout the country. These buyers, whether multiple retailers,
wholesalers or dealers, will be buying to supply numerous retail outlets and
they may buy from few sources or many, according to their judgments of how
demand can most profitably be met. Retailers may buy at points of first sale, or
from wholesalers, or from dealers
78
capable
of satisfying their particular requirements. Thus marketing runs in some well
established channels, which result from individual businesses keeping to
arrangements they find satisfactory rather than from any specific links between
types of buyers and sources of supply.
157.
As regards overseas suppliers and retailers in this country, the links are
different and just as diverse. Beef is imported fresh, chilled and frozen. Fresh
beef is supplied from the Republic of Ireland, in the form of fat cattle for
immediate slaughter, or as carcase beef and the meat must be marketed within the
same time as home production. Chilled beef can be preserved for a few weeks with
care and cost, but has to be marketed quickly once it is taken from the ship.
Frozen beef can be stored for longer, up to a year, and is transferred from the
ships hold to a cold store in the United Kingdom. Most imported lamb comes
frozen from New Zealand (in 1967, nearly 300,000 tons out of total imports of
nearly 340,000 tons) and can also be put into cold store on arrival in this
country. The quantity marketed or retained in cold store on arrival depends on
the time of the year and the state of the market.
158.
The major supplier of chilled beef has been Argentina. This trade has been
conducted on a consignment basis, sold on commission in the United Kingdom.
There are in this trade firms who conduct all the operations from purchase of
cattle, through slaughter and shipping, to sale in the home market. The final
sale may be through their own retail outlets, wholesale by private treaty, or
through a wholesale market such as Smithfield. Chilled beef is widely accepted
as an alternative to fresh beef and hence is in competition with it, although
sold at about 3d. per lb. less at the wholesale level. Chilled beef is therefore
sold at prices according to the state of the fresh meat market a few days after
its arrival in the United Kingdom. Those engaged in the trade have had to judge the market some four
to six weeks ahead, in the light of probable competition, particularly from home
and Irish beef supplies, but also from other meats. The price paid to
Argentinian producers depends largely on those traders judgments. South
American countries, like other southern hemisphere suppliers, produce the main
part of their fatstock between January
and
June, and thereby complement home produced and Irish grass-fed supplies. The
contribution of South American countries to United Kingdom meat supplies, which
was about ten per cent of the total in 1967, fluctuates between four and twenty
per cent at different times of the year. Also, the demand for imported meat is
higher in some parts of the country than in others; in Smithfield Market, for
example, in recent years, beef and veal from South America has amounted to about
forty per cent of the total quantities of such meat passing through the market
annually.
159. Frozen beef has been
imported mainly from Australia, South America, and New Zealand; there has also
been a number of minor suppliers. Frozen beef is not competing directly with
fresh or chilled beef; it goes mainly to catering and manufacturing uses, and at
much lower prices. The slaughter of cattle for this trade shows a seasonal
variation but the possibility of storing the meat makes its issue from store
onto the home market depend largely on the state of the market. Some frozen beef
is shipped in boneless cuts and there is a market preference for this.
160. New Zealand lamb is produced fat
between December and July, with a peak from January to March. Shipments are made
to the United Kingdom
79
during
this period and issues from cold stores here are governed by the state of the
market. New Zealand lamb is highly competitive with home produced lamb and it is
sold for most of the year at a lower price.
161.
Several countries supplying meat to the United Kingdom have their own
organisations which oversee and aid their exports. However the trade is also
conducted by firms which purchase oversee, and ship and wholesale in this
country both by private treaty and on the wholesale markets. In addition some
overseas shippers sell through agents in the United Kingdom. Thus most imported
meat is sold here by firms which are directly concerned with marketing in the
United Kingdom and form an integral part of the wholesale trade. Some of the
firms are further integrated in that trade in that they deal with both home
produced and imported supplies.
162.
Under the Bledisloe arrangements, the South American meat suppliers have been
permitted to export considerable quantities of meat to this country under less
stringent animal health safeguards than are applied to other exporting
countries. This has no doubt been done for trade, supply and price reasons. The
cessation of supplies from South America would entail the loss of perhaps as
much as 140,000 tons of beef and veal, which is under ten per cent of present
annual United Kingdom consumption; this would include 120,000 tons from
Argentina (which might be valued at about £25 million c.i.f.) and 10,000 tons of
beef from Uruguay (worth £2-£2½
million). About 15 per cent (worth about £2 million) of the total supply of
imported offal would also be lost. This might be replaced, probably with a
marked price effect, from other countries. The main problem would arise over
chilled beef which initially at any rate could only be replaced to some extent
by supplies from European sources. It might take some years for such a trade to
build up to really adequate proportions. If full replacement were needed, it
would have to be met largely by increased home production, more particularly of
pork and poultry meat in the short run, but of beef here and in Ireland in the
longer run.
163.
Chilled beef, of which Argentina has been our largest supplier and for which we
have been her principal customer, is acceptable at retail as an alternative to
fresh beef. It is usually cheaper cut for cut than home killed beef of similar
quality. A shortage of this meat would in the short-term increase the prices of
beef in particular and of other meats generally. In the longer term, assuming a
switch in demand to pigmeat and table poultry and the scope for increased
production and imports suggested above, the effect would be for the price
increase to be reduced but still to remain above the level whichother things
being equalmight otherwise have prevailed. Many of our witnesses thought that
the effect might be to divert consumers from beef to the detriment of livestock
enterprises in this country.
164.
In addition to the economic considerations above there are social and political
considerations which may make it impracticable to apply a total ban on all
carcase meat and unprocessed offal from countries where foot-and-mouth disease
is endemic; in view of this we outline in the next paragraph an alternative
modification to import policy.
165.
We have pointed out in paragraphs 14 to 17 that the most likely way in which the
foot-and-mouth disease virus is introduced into this country is in the bone
marrow, offal and lymphatic glands of infected carcases.
Further
80
we
have been advised that if the import policy were to allow for the importation of
only boned-out meat, and offal which had been processed in such a way as to
destroy the virus, the risk of introducing the virus would be substantially
reduced. If the present import policy were modified in this way we think its
effect in reducing the risk would be almost equivalent to a complete
ban.
166.
We have taken evidence from meat exporting and importing organisa-tions about
the practical problems involved in sending boned-out meat to this country. The
trade in boned-out meat from South America is already quite substantial. In
1968, for example, our imports of boned and boneless chilled or frozen beef and
veal from South American countries amounted to 3,110 tons, that is about 5 per
cent of their total exports of beef and veal to the United Kingdom in that year.
It follows that some exporters in South America are already equipped to carry on
this trade. Such equipment requires consider- able capital investment, and a
further extension of this trade would probably involve some alteration to
shipping arrangements.
167.
There are two obstacles in the present trading arrangements that would impede
the natural development of trade in boned-out meat. At present boned-out beef
and veal from countries not enjoying Commonwealth preference attracts 20 per
cent duty as opposed to a duty of about 3 per cent applying to chilled, fresh or
frozen beef and veal carcases. If a boned-out meat policy were to be adopted we
consider that it would be essential that the Government would adjust the import
duties on meat so as to remove the current discrimination against boned-out
beef.
168.
The second obstacle concerns new Regulations which were introduced in August,
1968 governing the inspection of imported food including meat; they replaced
Regulations which had been in force since 1937. The earlier Regulations
permitted meat to be imported without lymphatic glands if these were necessarily
removed in the preparation of the meat. Increasing trade meant that more meat
was being imported without these glands and because of the risk to public health
it was considered that this trend should not be allowed to continue. (Inspection
of glands is used in assessing the fitness of food for human consumption.) The
new Regulations require that some cuts of meat, particularly boneless, which
could previously be imported without lymphatic glands, must now have the glands
attached to them. The Regulations provide for exemptions where conditions in the
meat plants justify them; so far no South American establishments have been
exempted. The inclusion of lymphatic glands in consignments of boned-out meat
would undermine the purpose of a boned-out meat policy since lymphatic glands
may harbour the foot-and-mouth disease virus (see paragraph 14); it would be
necessary to impress upon the Governments of these meat exporting countries the
importance of attaining a high enough standard of hygiene for establishments to
earn exemption. Two veterinary attaches in Buenos Aires maintain liaison with
Argentina, Brazil, Chile and Uruguay on the animal health and public health
aspects of the meat trade. This we consider inadequate bearing in mind the
magnitude of the operation and the distances involved. If the complement were
increased it would enable the attaches to make a more effective contribution to
the attainment of the high standards referred to above. An increase in the
complement would also strengthen the operation of the Bledisloe
arrangements.
81
169.
Another obstacle that might impede the development of a boned-out meat policy
was brought to our attention by the representatives of meat whole-salers and
retailers in this country. They pointed out that consumers preferences varied
and that butchers cut their meat in a number of different ways according to
locality; they considered therefore that the enforced imposition on the consumer
of imported meat in the form of boned-out meat packs would be less acceptable
both to the trade and to the housewife. Notwithstanding these objections, there
is a trend in current commercial practice away from the exportation of carcase
sides towards boned-out cuts, and in any case a boned- out meat policy would
only affect what is at present about ten per cent of our total domestic
consumption of beef.
170.
Certain food processors in this country suggested to us that, if there were to
be any restriction on the importation of carcase beef and offal from countries
where foot-and-mouth disease is endemic, a system of licensing might be devised
to allow imports to continue to certain establishments in Great Britain who
undertook to adopt adequate precautionary measures. It is questionable whether a
satisfactory system of licensing could be devised.
171.
Another suggestion made to us was that the distribution of carcases imported
from countries where foot-and-mouth disease is endemic should be confined to
urban areas. The primary distribution of chilled beef from Argentina already
conforms in the main to this pattern. To impose such an arrangement on all
supplies of carcase meat from countries where the disease is endemic would
require policing not only of primary but also of subsequent distribution, and we
consider this to be impracticable.
172.
We examined the application of irradiation as a means of eliminating
foot-and-mouth disease virus from meat. A major problem would be that of
establishing the wholesomeness of the irradiated product, and even if this were
achieved the public would have to be persuaded to accept it. We do not therefore
think this method of control has any practical application at
present.
(b)
Slaughter Policy
173.
The slaughter policy has been applied in controlling the spread of
foot-and-mouth disease in Great Britain for the greater part of this century.
The procedures involved in carrying
it out have already been briefly described in Chapter VI. Although there have
been repeated outbreaks, including some major epidemics over the years, the
slaughter policy has been highly successful in limiting the extent of almost all
the outbreaks, and on all occasions it has been the major factor in eradicating
the disease, and eliminating the virus, from this country. In short, the
slaughter policy has prevented the disease from becoming endemic in Great
Britain.
174.
The annual costs in compensation for the slaughter of livestock from 1954 until
1968 are set out in Table XI opposite. Although in some years the cost of
compensation was high, the annual average over the period (but not including
1967/1968) was about £½ million. The cost of an outbreak, however, cannot merely
be assessed in terms of compensation. Other factors must also be taken into
account such as consequential losses and disturbance to the agricultural and
other industries, as well as to many activities which are
82
indirectly
affected. These factors were discussed in our assessment of the cost of the
1967/1968 epidemic (see paragraphs 97 to 101).
TABLE
XI
Annual
Cost of Compensation for Slaughter of Livestock, Resulting from Foot-and-Mouth
Disease, 1954 to 1968
|
Year |
Outbreaks |
Animals
Slaughtered |
Compensation |
|
Cattle |
Sheep |
Pigs |
Goats |
Total |
|
1954
..
..
1955
..
..
1956
..
..
1957
..
..
1958
..
..
1959
..
..
1960
..
..
1961
..
..
1962
..
..
1963
..
..
1964
..
..
1965
..
..
1966
..
..
1967
..
..
1968
..
..
|
12
9
162
184
116
45
298
103
5
0
0
1
34
2,210
187 |
527
664
10,547
11,284
9,529
2,251
26,045
7,078
371
0
0
154
5,964
196,771
18,096
|
377
713
13,123
12,885
2,442
2,284
32,493
9,813
273
0
0
0
38,607
97,253
11,582 |
391
241
4,793
6,221
8,008
3,179
12,031
8,149
308
0
0
0
718
113,267
5,259
|
0
5
42
20
24
3
24
9
0
0
0
0
2
50
7
|
1,295
1,623
28,505
20,003
30,410
7,717
70,593
25,049
952
0
0
154
45,291
407,291
34,944 |
£41,068
£55,940
£824,658
£880,586
£869,563
£225,370
£120,745
£679,540
£26,869
0
0
£18,895
£933,249
£24,621,578
£2,356,219*
|
*Provisional
figure.
Source: Ministry of Agriculture
175.
We consider, as did nearly all our witnesses, that the slaughter policy has been
an essential measure in controlling foot-and-mouth disease in Great Britain, and
that irrespective of whether a vaccination policy were adopted, slaughter would
need to be continued. Nevertheless we recognise the consequences of this police to farmers
and to those who have to implement it. We fully subscribe to the views expressed
by the Gowers Committee who wrote as follows:
We wish to make it clear at the
outset that we are not among those
those who regard
stamping-out [the slaughter policy] with complacency. We sympathise with the widely
expressed view that it is a crude and primitive
way of
dealing with a disease. We know what a harrowing duty it is for
the
officers of the Ministry who have to carry it out. We recognise the mental anguish it may
cause to those who suffer its consequences, and the shattering disaster, not
computable in terms of money, that it may bring to a farmer who has to see the
work of a lifetime destroyed in a day.
(c)
Vaccination Policy
176.
In the previous chapter we have described the vaccination procedures practised
in various countries under their foot-and-mouth disease
control
83
programmes,
and in the following paragraphs we outline the way in which such procedures
might be applied in Great Britain. We will deal with this aspect under five
headings:
(i) general prophylactic
vaccination;
(ii) ring vaccination following an outbreak of foot-and-mouth
disease;
(iii) emergency ring vaccination;
(iv) barrier vaccination;
(v) prophylactic area vaccination.
General Prophylactic
Vaccination
177.
The Ministry of Agriculture pointed out that before compulsory general
prophylactic vaccination for foot-and-mouth disease could be introduced in Great
Britain, an amendment to the Diseases of Animals Act, 1950 would be necessary.
An Order under the amended Act would also be required.
178. We describe in broad outline one of the ways in
which general vaccination might be applied in Great Britain. For this purpose
the following assumptions have been adopted:
(i)
All cattle and sheep over three months of age, but not pigs, would be vaccinated regularly.
(ii)
If an outbreak occurred the slaughter policy would be applied and all clinically
affected animals and animals with which they had been in contact would be
destroyed.
(iii) when an outbreak occurred all
cattle, sheep and pigs in an area approximately five miles around it would be
vaccinated.
(iv)
Vaccination would be under veterinary control.
179. Under such a scheme about 10 million cattle and about
21 million sheep would have to be vaccinated. In the first year two doses of
vaccine would be given in order to achieve as rapidly as possible a satisfactory
level of immunity. Thereafter one dose of vaccine would be given each year.
Similarly young stock would be vaccinated twice in twelve months once they had
reached three months of age, and then annually. Trivalent inactivated vaccine
containing types A, C, & O virus would be used since these types are present
in Europe and South America (see Map I).
180.
Vaccination would be carried out by local veterinary inspectors or by lay
assistants under their supervision. Inspection of livestock prior to vaccination
would be essential to detect any low grade infection that might be present in
herds and flocks.
181. Primary
outbreaks of foot-and-mouth disease, with secondary spread, could still occur as
the immunity conferred by general vaccination would be by no means absolute. It
would be impossible to keep all livestock completely protected at all times, and
pigs, which are highly susceptible to the disease, would still be at risk.
Nevertheless, raising the resistance of the national herd should reduce the
number of outbreaks to some extent in the first year of the vaccination scheme
and to a substantial extent subsequently.
84
182. Outbreaks of foot-and-mouth
disease would continue to be dealt with by the slaughter of all infected animals
and animals that had been in contact with them. Sanitary control and restriction
of movement of animals would
also be enforced. In addition, ring vaccination with appropriate
monovalent vaccine (see paragraph 123), of all susceptible stock over the
minimum age within a radius of five
miles from the Infected Premises would be carried out, together with veterinary
inspection of stock. The veterinary
resources of the area would be
utilised but it might be necessary to bring in additional vaccination
teams. There would be some delay in
starting ring vaccination but it would probably be complete within seven days of
the occurrence of the outbreak.
183.
In the field, regional veterinary officers of the Ministry of Agriculture would
ensure that vaccination programmes were devised and implemented. At the ports receiving cattle from
Ireland, the Ministrys veterinary officer in charge would ensure that all
imported store cattle and sheep were vaccinated; the number would amount to
about 400,000 head of livestock each year.
184. After the first injection of
vaccine and before the second dose had been given, control measures similar to
the present ones would be maintained in the event of an outbreak of
foot-and-mouth disease. The slaughter policy would be implemented to the same degree as at
present and restrictions relating to Infected Areas would operate. Local control centres would be set up
and the staff in charge, in addition to their normal duties, would be
responsible for ring vaccination.
The present routine patrol system of inspecting stock in a two ring round
an infected farm could be replaced by a clinical examination at the time of vaccination in a
five-mile ring. Because of the
possibility that vaccinated animals that had been exposed to infection might
develop a mild form of the disease without showing obvious clinical signs, it would be necessary
to
carry out subsequent routine inspections of the vaccinated animals.
185. After the second dose had been
given the immunity developed in the
national herd should allow modification of the existing control measures
in the event of an outbreak of foot-and-mouth disease. The slaughter policy, and
procedures on Infected Premises, would be continued, but restrictions relating
to Infected Areas could be much less rigid and applied only to the areas covered
by ring vaccination. Infected Areas would be maintained for 28 days to allow
time for the completion of ring vaccination and the development of satisfactory
immunity.
186. It would be essential that vaccine
used in a vaccination scheme should be both safe and efficacious; detailed
methods of production and control
would have to be formulated and embodied in Regulations. Only those batches of vaccine which
complied with the Regulations and which had been approved by the licensing
authority (the Ministry of Agriculture) would be used.
187. A
control laboratory acting on behalf of the Ministry of Agriculture would carry out tests
on batches of the finished product and on samples taken at various stages in the
process of manufacture. The Animal Virus Research Institute would probably be
the most suitable place for a control laboratory. The facilities would, however,
have to be expanded since the work on control should be entirely separate from
that of other work in the Institute in order to avoid cross-contamination which might
invalidate the results of control
tests.
85
188.
In formulating Regulations, important factors would have to be taken
into
consideration,
as follows:
(i)
the strains of foot-and-mouth disease virus to be used;
(ii) the tissue substrate
for cultivating the virus;
(iii) the initial concentration of
live virus particles;
(iv) the method of inactivation of
virus;
(v) tests for inactivation
(safety);
(vi) tests for antigenicity
(immunizing power).
It
was clear from the evidence we obtained from experts in the field of vaccine
production and control that considerable divergence of opinion existed regarding
some of the above factors. It was also clear that some of the procedures at
present employed are by no means satisfactory. For example, in some laboratories
inactivation of virus by formaldehyde is carried out in the presence of an
aluminium adjuvant, a process which in our opinion does not lend itself to a
safe final product. An advisory body to the Ministry of Agriculture, consisting
of expert virologists with knowledge of viral vaccines, would be desirable to
advise on the formulation of Regulations. This body would also advise on the
acceptability of new manufacturing and
control procedures as they arose.
189.
General prophylactic vaccination need not necessarily cover the entire
susceptible livestock population in order to be successful (see paragraph 115);
but it would be ideal if a coverage of 70 to 80 percent were achieved. In most
countries employing prophylactic vaccination only cattle are vaccinated and in
general this affords an adequate coverage. In Great Britain however vaccina-
tion of cattle only would cover 25 percent of the livestock population and it
would therefore be necessary to vaccinate both the sheep and cattle populations
for vaccination to be effective. Such a coverage could reduce both primary and
secondary outbreaks of foot-and-mouth disease. Any outbreaks that might occur
would probably be in pigs, young sheep and calves.
190. One of the problems associated with
vaccination is that it might induce in some animals an anaphylactic type
reaction (sensitivity to the injection of foreign protein). We do not know the
frequency of these reactions; the
factors present in the vaccine which may be responsible for them have not
yet been clearly defined. This is a problem that needs further investigation and
one which must be taken into consideration when embarking on a vaccination
scheme.
191. A
general vaccination policy in Great Britain would be costly as about 30 million cattle and sheep over three
months old would need to be vaccinated twice in the first year and thereafter
annually. Further, in the event of an outbreak of foot-and-mouth disease, all
the animals included in a prescribed area around the outbreak would be
vaccinated. It has been estimated that during the first year of the scheme, the
cost of general vaccination, with additional vaccination in the event of outbreaks
and with provision for the costs of
slaughter, might be of the order of £13 million and in succeeding years
about £5 million. The general vaccination would account for about 90 percent of
these total annual costs. In 1954 the cost of general vaccination of cattle,
sheep and pigs was given in the Gowers Report as a range from £24 million to £56
million per annum of which £10 million to £23 million related to vaccination of
cattle. General vaccination would be cheaper today partly because
vaccines
86
are
now likely to be less costly and also because, except in the first year,
vaccination would take place annually. In 1954 it was considered necessary to
vaccinate animals at four monthly intervals.
192.
There would also be a heavy cost in manpower. A considerable number of veterinarians
would be required to implement the scheme and as a result they would not be
available for other important veterinary work. There would also be a
considerable diversion of effort for farmers in rounding up herds and flocks and
mustering animals for vaccination. Farms have increased in size without a
proportionate increase in manpower, and the handling of individual animals
presents problems. The population of sheep in Great Britain in the Autumn is about 20
million and these would have to be included in the vaccination programme because
of their close contact with other farm animals. This could present practical
difficulties, particularly because many of them are in hill flocks. Moreover
vaccination would be difficult to justify in some areas where the disease has
been completely absent for many years.
193. Another problem would arise
from the considerable movement of cattle in Great Britain. The fear has been expressed that because
of this, many animals would be missed in a scheme of general vaccination. This problem could only be overcome by the costly procedure of identifying
individual animals.
194. It has been claimed that any form
of vaccination in Great Britain would deprive the country of
some of its valuable export markets in livestock because of the possibility that
vaccinated animals might be carriers of the virus,. Although we do not think
that there would be a high risk of transmission of the disease to other
countries by carrier animals we nevertheless recognize that it would be
difficult to overcome the traditional attitude of many countries importing
livestock, to receiving breeding stock from vaccinated herds. There would be no
problem in relation to those countries where vaccination is practised, but in
other countries there could be resistance. A system similar to that in use for exporting cattle from
Europe to Canada might have to be adopted. This system allows the importation of
young animals subject to testing for the presence of the virus, before they are
moved from the country of origin and again while held in quarantine in suitable
premises on arrival at their destination. The level of United Kingdom livestock
exports during 1965 to 1967 is given in Table XII. In 1967 the value of
these exports was about £1.2 million.
TABLE
XII
Exports
from Great Britain of live animals for breeding
(head)
|
Receiving
country |
1965 |
1966 |
1967 |
|
|
Irish
Republic
..
Commonwealth
Countries(including
Northern
Ireland
and Canada)
Europe
(other than
Irish
Republic)
Other
countries (in-
Cluding
U.S.A) |
4,876
cattle
5,358
sheep
104
cattle
134 sheep
1,302
cattle
1,750
sheep
484
cattle
484
sheep |
4,492
cattle
1,104
sheep
230
cattle
57
sheep
1,395
cattle
814
sheep
1,216
cattle
566
sheep |
5,022
cattle
208
sheep
519
cattle
129
sheep
789
cattle
509
sheep
1,397
cattle
694 sheep |
|
|
|
|
|
|
195.
Semen exports would probably be affected by vaccination in the same way as
livestock exports. The present export trade in semen is small but it is growing;
in the twelve months from 1st August, 1967 to 31st July,
1968 16,560 doses (worth about £19,500) were exported. During the year from
1st August, 1968
exports are expected to increase to about 25,000 doses(worth about £ 33,300).
The estimates for 1969/1970 are 56,000 doses (worth about £100,000) and for
1970/1971, 63,500 doses (worth about £120,000). It seems that vaccination would
present difficulties for exporters of both livestock and semen, but if the
demand is strong enough they could be overcome with the imposition of quarantine
restrictions and testing.
Ring
Vaccination following an Outbreak of Foot-and Mouth Disease
196. Ring vaccination is directed against the
spread of foot-and-mouth disease and to attain the best results should be
introduced immediately an outbreak occurs. Difficulties can arise if it is
applied at a late stage in the development of an epidemic (see paragraphs 206
and 208). One of the ways in which ring vaccination might be applied immediately
an outbreak occurs in Great Britain is described as
follows:
(i)
At every initial outbreak, a vaccination area would be declared. The shape and
size of the area would depend on the circumstances of the
outbreak.
(ii)
Additional vaccination areas, extensions or amalgamations would follow depending on the pattern of
subsequent outbreaks.
(iii)
Within each vaccination area, all cattle and sheep over three months and all pigs over two months of age
would be vaccinated.
(iv)Vaccination
would be started both at the centercentre and
at the periphery. All stock would be inspected by a veterinarian prior to
vaccination; this
would be
particularly impo9rtant
within two miles of the infected premises, Andand it
would replace the present patrol procedure.
(v) It is estimated that the type of
virus would be identified within two hours of suitable material for diagnosis
reaching the Animal Virus Research Institute. Sub-typing may require from twelve
hours to three days.
(vi)If
the sub-type cannot be identified rapidly, a polyvalent vaccine containing the
expected sub-types could be used forvaccination.
(vii)Stocks of suitable vaccine prepared
from the predicted types or sub-types would have to be
maintained.
(viii)Immediately an
outbreak was confirmed, vaccine sufficient for at least two days vaccination would
be dispatched to the area. Thus vaccination could commence on neighbouring farms
on the day following confirmation. Further supplies, and a reserve to
accommodate extensions, would be put into local cold stores.
(ix)Vaccination
of all stock in the first area would be completed within five to seven days of
confirmation of the disease and in additional areas within a further four to six days.
The speed with which vaccination could be
completed would depend upon the number of veterinarians and lay assistants
working under veterinary direction that could be assembled rapidly. It is likely
that each vaccinator could inoculate between 500 and 600 animals each day.
Single outbreaks could easily be dealt with but a rapid build-up of new
outbreaks, requiring additional staff, could present
difficulties.
88
197. The slaughter policy would still be
implemented on any farm where
foot-and-mouth disease was diagnosed, whether the stock
were vaccinated or unvaccinated. Cleansing and disinfection of infected premises
would be carried out. Stock
would be inspected in a two mile ring around the outbreak to discover infected
animals not showing obvious clinical signs, a condition which might occur as a
result of partial protection from vaccination. Those premises near the
centre would
be inspected each day at first and later at three-or-four-day intervals.
Those towards the perimeter would be inspected at five-to seven-day
intervals.
198. It is not easy to estimate exactly
the extent to which secondary spread would be limited. A number of factors are involved: the prevailing
weather conditions; the speed at which the ring vaccination is begun and
completed; the extent to
which markets are affected; the amount of the virus present at the initial
outbreak, and the rate at which spread of the virus takes place; and the time it
takes for immunity to develop following a primary vaccination. The Ministry of Agriculture
tried to estimate what effect a scheme of ring vaccination would have had on
past outbreaks. They thought that in
a large number
of outbreaks, ring vaccination would have had no effect on the spread
of the disease because they were entirely controlled by slaughter. In some major
outbreaks, however, ring vaccination would have limited considerably the extent of secondary spread; for
example in the 1967/1968 epidemic, if ring vaccination had begun early, the
number of outbreaks might have been reduced by about one half. This, however,
depends on certain assumptions which the Ministry of Agriculture made. Although
ring vaccin- ation implies a circle, and the word ring has been used in this
context,
the shape and size of the area would, we think, be highly important (see
paragraph 196(i)). We envisage that a more scientific method of defining the vaccination area
would be essential. The circumstances that would be relevant would include wind
and weather, stocking densities and movements. To assist in determining their
importance we think that it would be advisable to rely on the advice of a team of
experts comprising meteorologists, epidemiologists and veterinarians (see
paragraph 215).
199. We have considered the probable
cost of ring vaccination as an adjunct to slaughter. If outbreaks in the future
are assumed to be on the same scale as in the past, we think that the costs of
vaccine and vaccination would be largely offset by a reduction in the number of
secondary outbreaks that would be brought about, with consequential savings in
compensation for slaughtered stock. We do not think that the
annual cost of ring vaccination and slaughter would on average over a period of years
greatly exceed the cost of a slaughter policy alone. However, on the assumption
that there are no outbreaks at all,
there would still be an annual maintenance cost of rather less than £1
million; a ring vaccination scheme depends on the immediate availability of
vaccine and it would be necessary to carry a substantial stock which would have
to be renewed periodically when its useful life-about 12 to 18 months-was
exhausted. The estimate of cost for a stock of vaccine is based on a stock of 10
million cattle doses at 1/6d. per dose, together with an allowance for other
storage expenses.
200. The practical difficulties of ring vaccination are
considerable. One of the main
difficulties is the mustering of large numbers of animals at short
89
notice
which could cause them considerable stress particularly at certain times of the
year, such as at lambing and Spring calving times. In addition fog or snow could
create hazards for both men and stock; and there would always be difficulty in
bringing in all the stock. Another danger would be the removal of animals from
the relatively infection-free hills and outlying areas to farm steadings where
they would be more likely to be exposed to the disease.
201. It would be necessary, after,
vaccination, to inspect stock within a two- mile radius of the outbreak.
Occasionally, in the event of a prolonged outbreak it might even be necessary to
re-vaccinate all stock later.
202. There would also be a call on the
relatively small labour force available on farms. Furthermore farmers would be
reluctant to leave their farms to assist their neighbours if this entailed any
risk of introducing the disease to their own premises. They might also be
reluctant to allow vaccination teams
on their farms for fear of introducing the disease.
203. Ring vaccination has been
successful in Denmark and has not led to the disruption of the general practices
of marketing and the movement of livestock, but their experience in this respect
is not strictly applicable in this country. It is likely that the small amount
of movement of cattle in Denmark has contributed to the success of ring
vaccination in that country; in Great Britain, on the other hand, there is a much larger
movement of animals to markets. Denmark has only six major livestock markets
compared with over 1,000 livestock markets and fairs in Great Britain. Another
major difference is that there is much less exchange of animals between herds in
Denmark than there is here. In the dairy industry in this country there is
considerable movement of animals. Each year some 300,000 cows are sold in milk
or in calf together with 400,000 other cows, 1,250,000 calves and 100,000 dairy
store cattle; there are also private transactions which involve the movement of
animals from farm to farm. In addition to dairy stock movements there are large
movements of beef cattle, sheep and pigs. For instance young animals are often
reared in one district and moved to another for fattening.
204. Ring vaccination would make the
problem of restocking after an outbreak considerably greater than at present. It
is unlikely that there would be sufficient quantities of stock for purchase from
within the ring vaccination area and such as were available might be at a high
premium. Clearly it would be necessary to vaccinate animals that were moving
into the ring for some time after the outbreak.
205. There are also problems in moving
animals from inside the vaccinated area to farms outside. The Danish Government
permits such movement after 30 days following an outbreak. In March, 1968 the
European Commission for the Control
of Foot-and-Mouth Disease considered this problem in respect of exports of live
animals from areas of barrier vaccination and concluded that it would be wise to
allow three months to elapse after vaccination before moving animals for export
from a vaccinated area. Nevertheless there would be reluctance among farmers
outside the vaccinated area to accept cattle from within a vaccinated
ring.
206. We have already said that for ring
vaccination to be successful it should be carried out immediately an outbreak
occurs. It was suggested to us that vaccination might be delayed to allow some
assessment to be made of the possible development of an outbreak. This would be
entirely contrary to the whole
90
object
of the operation, and we therefore consider that ring vaccination, if
introduced, should be carried out as soon as an outbreak occurs. There may
however be occasional instances where livestock, because of their isolated
position, would present no significant risk. In such cases the mandatory
provisions might be waived.
207.
If, as would happen in the event of a large number of scattered outbreaks, large
areas of the country and large numbers, say fifty percent of animals were
involved in ring vaccination, then general prophylactic vaccination would
probably become inevitable.
Emergency
Ring Vaccination
208. We think that the adoption of
emergency ring vaccination as a policy after an epidemic had become established
would contribute little towards control and would probably lead to a policy of
general vaccination (see paragraphs 206 and 207). In the event of ring
vaccination becoming extensive it would be tantamount to barrier
vaccination.
Barrier
Vaccination
209. It is unlikely that barrier vaccination
would have much application in
this
country, but it might be necessary should an outbreak get out of
control.
Prophylactic Area Vaccination
210. It has been suggested to us that
prophylactic vaccination, limited to areas of high cattle density, might be used
to protect cattle in parts of the country where primary outbreaks were likely to
lead to epidemics. The selec- tion of areas on the basis of a high risk of
spread of foot-and-mouth disease would present difficulties. The west-Midlands
area, which was affected in the 1967/1968 outbreak, might be considered a
candidate for selection, and else- where density of stocking and intensive
dairying might be used as the criteria. Somerset, part of Devon, possibly part
of Wiltshire and part of Gloucestershire might then have to be considered. There
is an area of dense stocking in Cumberland, but it has never been involved in a
major crisis and in such a case the criteria might be waived. On the other hand,
there are many areas for which a case might be made out on the basis of past
difficulties, for example the Forest of Dean in Gloucestershire (see paragraph
61) and Dumfriesshire (see
paragraph 134). There is always a problem in relation to possible infection of
animals in unfenced areas where, for example, hill sheep populations could be at
risk (see paragraph 57). There have been occasions when east and south coast
counties suffered a high number of primary outbreaks which were associated with
infection from the Continent. But the position in Europe has now improved to the
extent that these southern and eastern coastal belts need no longer be regarded
as areas of particular risk in comparison with other parts of Great Britain (see
paragraph 139).
211.
We see considerable difficulties in implementing a scheme of this nature. When
the incidence of primary outbreaks of foot-and-mouth disease in other areas of
the country is examined no very clear pattern emerges; the distribution appears
to have been random. It would be extremely difficult, therefore, to select areas
for vaccination on any reasonable basis and we can see no benefit in applying
this method of control.
(d)
Other Treatments and Remedies
212.
We have received many other recommendations for preventing foot- and-mouth disease and controlling
epidemics; these have covered homoeopathy,
91
dietetics
and other practices. We consider there is no scientific evidence that at this stage they might have a part to
play in controlling the disease in Great Britain. Research work on
chemo-therapeutic substances with anti-viral properties, particularly in
relation to smallpox, is promising, and such work will undoubtedly be extended
to foot-and-mouth disease. At one time serum therapy, which produces a passive
immunity, was practiced in controlling the disease but the development of
vaccine, which produces an active immunity, has made this process
obsolete.
(e)
Research
213. Before 1964 the work of
the
Animal Virus Research Institute at Pirbright was confined almost
entirely to foot-and-mouth disease research; since then its main effort has
continued to be
concentrated on the disease but work has also been carried out on other viral
diseases of animals. The buildings at Pirbright are well designed and equipped
to prevent the escape of viruses and security measures are rigidly enforced. The
Institute has an independent Governing Body, and for the purpose of scientific
policy, administration and finance it is under the aegis of the Agricultural
Research Council. The work of the Institute has been directed towards basic
research, vaccine research and epidemiological studies. Before the 1967/1968
epidemic there was little opportunity for studying epidemiology in this country
and it has been recognized that one of the most useful methods of reducing the
risk of introducing the disease into Great Britain is in improving the disease
position abroad. To this end the Institute has given high priority to the
development of vaccines and the pro-motion
of vaccination programmes in overseas countries. It has been designated by the
Food and Agriculture Organisation of the United Nations as the World Reference
Centre for the typing of foot-and-mouth disease virus. We hope that the present
programmes of the Institute will be continued, and would like to see an
expansion, to include epidemiological studies in foot-and-mouth
disease.
214. The Ministry of Agriculture has a
Department of Virology at its Central Veterinary
Laboratory at Weybridge which is not at present involved in the study of
foot-and-mouth disease. We would like to see the Weybridge labora- tory staffs interest extended to
include work on foot-and-mouth disease in association with the work at the
Animal Virus Research Institute. We consider that work with live foot-and-mouth
disease virus should be restricted to the Institutes premises. It is also
desirable that some members of the Ministrys field veterinary staff whose
present duties include foot-and-mouth disease control in the field should be
given training in epidemiology with particular reference to this
disease.
215. Epidemiological teams, comprising
personnel from the Animal Virus Research Institute, the Ministry of
Agricultures Veterinary Laboratory Services Services
and Field Service, and supported by other appropriate experts such as
meteorologists, aero-biologists and statisticians, should be formed. These teams
would have two main functions. In an outbreak they would collect information by
studying the outbreak from the start, predicting its probable development and so
provide information which would help in formulating measures to control it. They
would also collect data for the purpose of future epidemiological studies. The
teams should gain experience in working together
before
outbreaks occur so that they would be fully prepared when their services were
required.
92
CHAPTER
VIII
RECOMMENDED
POLICY
216. Our recommendations for reducing
the risks of the introduction of foot-and-mouth disease, and
for controlling its spread, are based on a consideration of the various policies
including slaughter, import control and vaccination described in Chapter
VII, and on our judgment as to which of these are appropriate to Great
Britain.
217. We have shown in earlier chapters
that there are substantial gaps in ourscientific knowledge of foot-and-mouth
disease, particularly in relation to some
aspects
of epidemiology. It is not possible therefore to make recommendations
regarding
prevention and control policies purely on scientific
grounds.
218. We have attempted to assess the
gradient of risks of the introduction of foot-and-mouth disease in meat
and meat products. The degrees of risk will depend on Government policy.
The risks would be greatest if there were unlimited importation of meat and meat
products from all countries irrespective of their foot-and-mouth disease status,
and least if meat were imported only from foot-and-mouth disease-free countries
such as Australia and New Zealand. Between these extremes there are varying
degrees of risk depending on what restrictions are applied to imports of meat
and meat products and offal, and on whether such imports have their origin in
countries where the disease is sporadic and the risks are less, or in countries
where the disease is endemic and the risks are greater. We have pointed out that
the major risks derive from the persistence of foot-and-mouth disease virus in bones, offal and lymph glands,
and we think that if a policy is adopted which excludes these dangerous
components, the reduction of risk would be almost equivalent to that which would
be achieved by a complete ban on meat imports.
219. Slaughter, which is the best method
of eradicating the disease, is essential whatever policy is adopted, but the
adoption of a policy which relies on the slaughter policy alone should, in our
view, be dependent either on a complete ban on imports, or at least on the
exclusion of the dangerous components of meat, from countries or areas of
countries where foot-and-mouth disease is endemic. If these dangerous components
are not excluded we think it essential that some form of vaccination should be
introduced.
220. General vaccination givens a large
measure of protection but this advantage has to be balanced against the
disadvantages attaching to the disturbance of normal farming practice, the
diversion of veterinary manpower and the very considerable cost (see paragraphs
177 to 195).
221. Ring vaccination would not limit
the number of primary outbreaks but it could limit spread. Although it has
considerable disadvantages (see paragraphs 200 to 205), we think that in certain
conditions ring vaccination could be a
useful adjunct to slaughter.
222.-I. We recommend that the slaughter
policy, which we consider to be
the best method of eradicating foot-and-mouth disease when it occurs in
Great
93
Britain,
should be continued. This policy by itself should only be adopted if the
conditions of meat import policy are such as to reduce substantially the
risks
of primary outbreaks occurring. If such conditions of meat import
policy
are not put in force we would recommend that the slaughter policy should
be reinforced by a ring vaccination
scheme (see paragraphs 173 to 175 and 196 to 206).
II.
The conditions of meat import policy which in our view are necessary to
enable
the slaughter policy by itself to be continued and which we recommend
are:
(a)
(i)
The
ban on imports of mutton, lamb and pigmeat from countries
or
areas of countries where foot-and-mouth disease is endemic
should continue (see paragraphs 150 and
152).
(ii)
Imports of mutton and lamb offal and pig offal from
countries
or
from areas of countries where foot-and-mouth disease is
endemic should be limited to offal processed in such a manner as
to destroy foot-and-mouth disease virus (see paragraphs 14 to
17, 144, 164 and 165)
.
(b)
Because there is a high risk of introducing foot-and-mouth
disease into Great Britain by importing carcase beef
and
beef and
beef offal from Countries or from areas of countries where
foot-and-mouth disease is endemic, on strictly animal
health
grounds
there
should be a complete ban on all
such imports (see paragraphs
14 to 17 and 144 to 170).
( c)
Alternatively if for social, political or commercial reasons the
recom-
mendation in (b) is not accepted, imports of carcase beef and beef
offal from countries or from areas of countries where
foot-and-mouth
disease is endemic should be limited to-
(i) boned-out beef (see paragraphs 14 to 17, 165 and 166);
and
(ii) beef offal processed in such a manner as to destroy foot-and-
mouth disease virus (see paragraphs 14 to 17 and 164 to
165).
III. We recommend
that:
(a) Our veterinary staff in
South American countries should be strengthened
in order that standards of public health inspection acceptable to
the
British Government can be ensured and so render the retention of
Lymph glands in boned-out cuts of meat unnecessary, and in order
to
Assist the implementation of the Bledisloe arrangements (see
paragraph
168).
IV. We recommend that contingency
plans for the application of ring vaccination should be kept in constant
readiness,. They could be put into operation Should our recommendations in II
not be successful in limiting the number of Outbreaks (see paragraphs 196 to 206
and 221).
94
V. We recommend that the importation of
meat and meat products from all Sources be subject to revocable conditional
licences (see paragraph 146.).
VI. We recommend that adequate
facilities for clearing and disinfection of Vehicles and persons engaged in the
transport of livestock should be a legal Requirement at appropriate points of
entry into Great Britain(see paragraph 141).
VII. We recommend an expansion of
research work on foot-and-mouth Disease, particularly in epidemiology, on the
lines suggested in paragraphs 213 to 214, and the use of epidemiological teams
in the field (see paragraphs 198 and 215).
223. A dissenting note, by Anthony
Cripps, Q.C., follows.
Signed
NORTHUMBERLAND (Chairman)
ANTHONY CRIPPS
DAVID G. EVANS
C. HENRY PLUMB
ERIC L. THOMAS
EDWARD
THOMPSON
DAVID WALKER
WILLIAM L. WEIPERS
JOHN
N. JOTCHAM (Secretary)
MELBA
D. WHITE (Assistant Secretary)
7th
March, 1969.
95
DISSENTING
NOTE
by Anthony Cripps, Q.C.
1. The
extent of my dissent from my Colleagues is that I would delete the second and
third sentences of Recommendation I; substitute We recommend for the first
three lines of Recommendation II; and substitute for the second sentence of
Recommendation IV They should be
put into operation whenever an outbreak occurs. In short, the immediate application of
ring vaccination to any outbreak which occurs seems to me essential. That I am
unable to agree with
them is a matter of personal regret since I have the highest admiration for the
completely disinterested and impartial approach and final judgments of all those eminent and
discerning men in so many different walks of life with whom I have had the
privilege and pleasure of studying the various problems over the last
year.
2.
There are two basic reasons for this dissent. First, I do not consider that any
diminution in the risk of introduction of the virus to be anticipated from any
meat import policy in relation to countries where the disease is endemic and
from any improvements in the disease situation abroad is at present sufficiently
certain to reduce the risk of introduction─ from
anywhere in the worldto, or almost to vanishing point. Secondly, we are now at
a stage at which it must be a matter of no more than estimate to what extent
that risk will be reduced by a hitherto untried meat import policy while in
about six years time we shall know as a matter of fact how far any
such meat import policy has or has not been successful in reducing that
risk.
3.
Every diminution in the risk of introduction of virus into the country reduces the number of occasions
upon which the risk of the disease spreading can arise. If the risk of
introduction is reduced to, or nearly to, vanishing point, then the risk of any
spread is correspondingly reduced either to
vanishing point or to the point at which the risk of spread will arise so
very rarely that it may be reasonable to take less stringent precautions against
spread than would otherwise be considered necessary. The vital question upon the answer to
which should depend the policy to adopt in future seems to me therefore to be
whether or not the anticipated diminution in the risk of introduction of the
virus into this country will reduce that risk to, or nearly to, vanishing
point.
4.
In considering the extent to which diminution in the risk of introduction of the
virus into the country is likely, one possible if not particularly convincing
approach is to start from whatever evidence is available as to past
introductions and their origins, then to make allowances both for improvements,
recent or anticipated, in conditions generally and for improvements to be
anticipated from any new meat import policy, and finally to try and arrive at
some estimate the extent to which the risk of introduction is likely to be
reduced. The evidence as to the
origins of past introductions is sparse and consists of attributions to probable
origins of primary outbreaks made by the Ministry over the period 1954 to 1967,
excluding the 1967/1968 Oswestry outbreak.
All these attributions are not necessarily correct; many have had to be
made on much less evidence than was desired; but the general picture presented
by them is probably not misleading.
From Table X in paragraph 148 these attributions show 74
97
out
of 179 (41 %) only attributed positively to endemic countries. Certainly some of the remainder would
have been attributable to endemic countries if more facts had been known, but I
see no reason to think that this addition would be any particular proportion,
because there is so much uncertainty underlying these attributions. This leaves 59% attributable to
non-endemic countries or about which we really know very little. This percentage of origins which are
either obscure or not positively connected with any endemic country is
disturbing. Another approach
is to forget all about past attributions and to form a judgment based on a
general appreciation of all the evidence we have received over the past
year. Here again the impossibility
of arriving at a view purely on scientific grounds, and the substantial gaps in
our scientific knowledge of the disease, mentioned in paragraph 217 emphasise
that while there is now a wide area of what is known there is also a wide area
covered by the element of the unknown.
While a suitable meat import policy would substantially reduce risk of
introduction from endemic countries (or possibly eliminate it), it would not
have the slightest effect on risk arising otherwise than from meat or arising
from non-endemic countries. I can
find no evidence to justify the inference that any such policy would necessarily
reduce that risk of introduction from everywhere to or almost to vanishing
point, even if one makes to the best of ones ability allowances for improvement
in conditions on the Continent since 1954 and to be anticipated in the coming
years.
5.
When virus succeeds in getting into this country one small introduction of the
virus could produce another epidemic, and all our witnesses who gave any view on
this matter agreed that it could not be said that another epidemic of Oswestry
proportions might not occur again at any time. This is the most vital factor in
showing the need for ring vaccination. The statistics of numbers of
outbreaks (primary and secondary) over the years support the view that an
epidemic is only to be expected something like once in about 20 years; but there
is no reason to think that this fatal year will in future occur at regular or
even moderately regular intervals.
It may next occur as well in 1970 or 1971 as in 1987 or 1988. Some
reduction in the risk of spread is to be anticipated from improvement in the
administrative arrangements connected with the slaughter policy, but those
arrangements (with which we shall be dealing in Part II of our Report) were not
so inadequate that this improvement can be expected to make more than a marginal
difference. Whatever the meat
import policy in relation to endemic countries may be, a definite risk of one
small introduction from somewhere and of a consequent epidemic in any one year
will remain. If possible therefore some other means of reducing this risk seems
to me to need to be found.
6.
Such a means exists in the modern weapon of vaccination, now more efficient and
less costly than at the time of the Gowers Report, (see paragraph 191). Through
this country is one in which the disease is not endemic we can no longer
consider it as being as geographically isolated as in 1954 with the immensely
increased passenger and vehicular traffic to and from Europe, the increased air
passenger traffic everywhere, and the increased knowledge of the extent to which
the disease may be wind-borne.
We are less isolated in some ways than the larger of those countries
which have been free of the disease for long periods, such as New Zealand,
Australia, and the countries of North America, and possibly than Ireland,
Iceland and Norway. But the
important characteristic in which we differ from all those countries is that,
for whatever cause, we have not
98
been
free of the disease for any period longer than 2Ύ years (and that only once)
since 1954, while all those countries have been free for the whole of that
period and longer. Had we been (or
if we should in future be) free for some substantial length of time, such as six
years, that would be a significant factor in relation to future policy and one
to which considerable weight ought to be given, because it would be a matter of
fact as opposed to one of theory or estimate. Those countries do not import meat
from endemic countries, and this may be the reason for their freedom from the
disease; it is not easy to suggest any other: but whether it is the reason or
not we shall be better able to judge by reference to fact after we have adopted
such a meat import policy as we recommend for six years than we are able to do
at the present time by reference to theory or estimate
only.
7.
General prophylactic vaccination may appear the sensible and scientifically tidy
solution. Its advantages and disadvantages are discussed in paragraphs 177 to
195. Costs in two countries in
which this is the policy work out at 4d. and 8d. a dose respectively, and little
needs to be added for administrative expenses since in one of them vaccination
was being successfully carried out by farm hands without any veterinary
assistance though with the knowledge that a veterinary surgeon (who had to be
notified in advance of any vaccination) might make a spot check on any
occasion. This should be able to be
done in this country. After the initial year or so it is difficult to see why
general prophylactic vaccination need cost more than a few shillings per beast
per year and this is well within the means of any farmer and would probably
represent good value for money. But
inspection (as opposed to vaccination) must always require veterinary
expertise. Additional
manpower consumed by farm workers and additional veterinary time should not be
great after the initial arrangements and basic training for farm hands have been
effected. Carrier animals may
create a risk in theory and it cannot be shown that there is no such risk, but
the absence of any known case where this risk had produced disease after
deliberate experimental attempts to do so, indicates that, until anything
further is known to substantiate this risk as more than infrequent and unusual,
it would be wrong to give much weight to it. The practical problems arising out of
application of such a policy will no doubt continue to be kept under review; in
a year or two improved vaccines effective in pigs and with a longer shelf life
will probably become available. But
general prophylactic vaccination has usually only been introduced as a second stage following after some more
limited form of vaccination, and there is of course a possibility that over the
next 20 years the number of outbreaks in this country may sufficiently decline
to make such a policy unnecessary: for these reasons only I would not recommend
general prophylactic vaccination at this time.
8.
Ring vaccination in the event of an outbreak is the policy which my Colleagues
consider could in certain conditions be a useful adjunct to slaughter (see
paragraph 221) and would recommend as a reinforcement of the slaughter policy in
certain circumstances. Though ring
vaccination in the event of an outbreak may be almost worthless for potentially
insignificant outbreaks, it will be of some, and may be of immense, value for
potentially epidemic outbreaks. In the latter cases, the evidence indicates
that, in certain conditions and on certain assumptions, about half the total of
farms only would have been affected after a potentially epidemic outbreak has
occurred if ring vaccination in the event of an outbreak were applied to the
outbreak as immediately as possible;
99
These
conditions and assumptions of course involve much that is uncertain, but were
such as to indicate that about half may well be a substantial underestimate of
what would have been unaffected.
The question of how much ring vaccination would have contained the
Oswestry outbreak is of course speculative, but a reasonable inference is that
of the 2346 farms at least 1170 would probably have been saved by ring
vaccination. This would have been worth doing. This view depends on knowledge
gained since that outbreak, but in the light of present knowledge it seems to me
to follow that the policy actually applied to the Oswestry outbreak was the
wrong policy for that outbreak. If general prophylactic vaccination followed
ring vaccination that would be no disadvantage, but would simply show that such
vaccination had unfortunately become necessary and therefore
desirable.
9.
Ring vaccination in the event of an outbreak combined with slaughter is open to
the criticism that it is from a tidy scientific point of view a half-way house
between the present policy of slaughter only and the complete policy of general
prophylactic vaccination with slaughter.
But the advantages of that policy, compromise as it may be, in terms of
probable practical results will be seen far to outweigh any disadvantages. If one tries to look into the future
realistically, the coming years can be divided into three
categories:
(1) those in which no
outbreaks at all occur in this country, in which there will be no vaccination because none will be
needed, but some cost
waste on control storage and renewal of vaccine;
(2) those in which
only potentially insignificant outbreaks occur, when
there will be a little vaccination but not much, rather less cost waste
on
control storage and renewal, possibly not a very worthwhile result but
useful experience will be gained in those years from small practical
applications of the policy; and
(3) those in which potentially epidemic
outbreaks occur, in which worth-
while
results will be achieved, and the first educative and preparatory steps will be
taken towards general prophylactic vaccination, should it unfortunately prove to
be necessary at a later stage.
No
one can possibly foresee into which category any one year will fall and there is
no evidence at present to justify the assumption that any one year will not fall
into the third category. It
is therefore advisable to take precautions against such a possibility now rather
than to wait until a later date by
which the fatal year may already have occurred again.
10.
The great objection to not combining a general policy of ring vaccination in the
event of an outbreak with slaughter is that this involves taking the risk that
one small introduction of the virus into this country may produce an epidemic of
Oswestry proportions in any year.
That risk appears to me entirely unacceptable at the present time when we
have not been free of the disease for more than 2Ύ years (and that only once) in
modern times. If how-ever at some future date the country were to have been
entirely free of the disease for some substantial length of time, such as 6
years, then I would consider that as important evidence that a less dangerous
stage had in fact been reached, and would then-but not before-make similar
recommendations to those which my Colleagues do now. For the present, therefore, I recommend
the immediate application of ring vaccination to any outbreak which may
occur.
Signed ANTHONY CRIPPS
7th March, 1969
100
APPENDIX
I
EVIDENCE
RECEIVED
The
following bodies or individuals have expressed views to us orally and/or in
writing. Those who gave written and oral evidence are marked with an
asterisk.
Aberdeen County
Council
Aberdeen and District Milk
Marketing Board
*Agricultural Research
Council-
Represented by Sir Gordon Cox, K.B.E., T.D., D.Sc., F.Inst.P.,
F.R.I.C.,
F.R.S.
Agricultural Research
Council Meat Research Institute
* Agricultural Research Council. Institute for Research on Animal
Diseases-
Represented by Dr. W. M. Henderson, D.Sc.,
M.R.C.V.S.
Anglers Co-operative
Association
Animal Health
Trust
*Animal Virus Research
Institute-
Represented by Dr. J. B. Brooksby, D.Sc., Ph.D., M.R.C.V.S.,
F.R.S.E.
Dr. F. Brown, B. Sc., M. Sc.,
Ph.D.
Mr. R. Burrows, B.Sc.,
M.R.C.V.S.
Mr. J. Davie, B.Sc.,
M.R.C.V.S.
Dr. G. N. Mowat, Ph.D.,
M.R.C.V.S.
Dr. R. F. Sellers, M.A.,
B.Sc., Ph.D., M.R.C.V.S.
Mr. H. H. Skinner,
F.R.C.V.S.
*Association of the British
Pharmaceutical Industry-
Represented
by Dr. P. B. Stones, M.R.C.S., L.R.C.P., M.B., B.S.,
M.Ph.,
F.C.Path.
Association of Chief
Police Officers of England and Wales
Association of County
Councils in Scotland
Association of
Municipal Corporations
Association of River
Authorities
Bank of London and
South America Ltd.
Bedford County
Council
Belted Galloway Cattle
Society
*Birds Eye Foods
Ltd.-
Represented by Mr. A. E. Hardwick
Mr. R. Symons, M.A.
Board of Inland Revenue
*British Agricultural Export
Council-
Represented by The Hon. F. N. W. Cornwallis, O.B.E.
Mr. A.
Jenkins
Mr. I. R.
Wylie
101
*British
Association of Meat Wholesalers Ltd.
Represented by Mr. E. W. P. Rimer
British Bacon Curers
Federation
British Broadcasting
Corporation
*British
Cattle Breeders Club-
Represented by Mr. P. Dixon-Smith, N.D.A.
Mr. D. W. Fattorini
British Cycling
Federation
British Field Sports
Society
British Friesian Cattle
Society
*British
Homoeopathic Association-
Represented by Mr. J. B. L. Ainsworth, M.P.S
Mr. G. Macleod, D.V.S.M., M.R.C.V.S.
Mr. E. S.
Ponsford-Raymond
Mr. A. L.
Wagland
Miss E.
Walker
British Insurance
Association
*British
Livestock Exports Ltd.-
Represented by Colonel D. Kennedy
British Railways
Board
British Semen Export
Ltd.
British Waterworks
Association
*British
Veterinary Association
Represented by Mr. J. A. Anderson, M.R.C.V.S.
Professor
W. I. B. Beveridge, M.A., D.V.Sc., D.V.M.,
M.R.C.V.S.
Miss W. M. Brancker, O.B.E., M.R.C.V.S.
Mr. P. B. Capstick, B.V.M.S., M.R.C.V.S.
Mr. J. A. Pasfield, O.B.E., M.R.C.V.S.
Compound Animal Feeding Stuffs
Manufacturers National Association Ltd.
Central Association of Agricultural
Valuers
Chandler, Hargreaves, Whittal & Co.
Ltd.
Chartered Land Agents
Society
*Cheshire
Agricultural Society-
Represented by Mr. F. Hughes
*Cheshire
County Council-
Represented by Mr. C. W. Hobson
Mr. J. H. Lord,
F.L.A.S.
Chief Constables (Scotland)
Association
Counties of Cities
Association
County Councils Association
102
*Country Landowners
Association
Represented by Mr. N. E. Strutt, T.D., D.L.
Crofters Commission
Dartmoor Livestock Protection
Society
Deneside School Youth
Association
*Department
of Agriculture and Fisheries, Dublin
Represented by Mr. M. J. Barry
Mr. H. G.
Foster
Mr. M. G. Hynes,
M.R.C.V.S.
Department of Education and
Science
(Combined with Central Council of Physical
Recreation)
Devon Cattle Breeders
Society
Devon County
Council
English Cross-Country
Union
Fatstock Marketing
Corporation
*Federation
of Wholesale Fresh Meat Traders of Great Britain and
Ireland
Represented by Mr. J. G. Blandford
Mr. H. E. Bywater,
M.R.C.V.S.
Mr. A. W.
Clift
Mr. J. F. Moore,
F.C.A.
*Farmer
and Stockbreeder
Represented by Mr. P. Bell, B.A.
*Farmers
Union of Wales
Represented by Mr. R. P. Davies
Mr. R. O.
Hughes
Mr. W. H.
Jones
Mr. G. Pugh
*Farmers
Weekly
Represented by Mr. M. Leyburn, B.Sc.
Mr. M. R. Williams,
B.Sc.
Flintshire County
Council
*Food
and Agriculture Organisation of the United Nations
Represented by Dr. P. R. Ellis, M.P.H., B.Sc.,
M.R.C.V.S.
*Food-and-Mouth
Disease Sub-Committee of Conservative Partys
Agricultural
Committee
Represented by Mr. J. M. Temple, J.P., M.P.
Gaskell Bros. Ltd.
*George
Wimpey & Co. Ltd.
Represented by Mr. C. J. Chetwood
Mr. R. N.
Oliver
Granada Television Ltd.
103
Hereford Herd Book
Society
H. Hobson and Co.
Home
Office
Horserace Betting Levy
Board
*Imported
Meat Trade Association Incorporated
Represented by Mr. R. J.
Collis
Mr. W. M.
Pooley, O.B.E.
*Institution
of Professional Civil Servants
Represented by Dr. P.
Dawson, B.Sc., Ph.D., B.V.M.S., M.R.C.V.S.
Mr. N.
MacGregor-Burns, M.R.C.V.S.
Mr. W. H.
Palmer
Mr. A. Taylor
M.R.C.V.S.
Jockey Club
John Morrell & Co.
Ltd.
Joint English
and Scottish Livestock Auctioneers Consultative Committee
Joint Turf
Authorities
Kidderminster Rural District
Council
Leicestershire
Schools Canoeing/Sailing Association
Lloyds
Master of Foxhounds
Association
*Mersey
and Weaver River Authority
Represented by Mr. M. C. Doody, M.B.E., M.Sc., M.I.C.E.,
A.M.I.W.E.
*Meteorological
Office
Represented by Mr. G. W. Hurst, B.Sc., A.R.C.S.,
B.I.C.
Mr. P. J. Meade, O.B.E.,
B.Sc., A.R.C.S.
Mr. L. P. Smith,
B.A.
Mr. P. B. Wright,
B.Sc.
Metra Consulting Group
Ltd.
*Microbiological
Research Establishment
Represented by Dr. C. E. Gordon Smith, M.D., M.R.C.P.,
M.C.Path.
*Midland
Marts Ltd.
Represented by Mr. F. R. Barker
*Milk
Marketing Board for England and Wales
Represented by Mr. C. R. Garnham
Mr. J. Jackson,
M.A.
Mr.
P. Jackson, M.A.
Mr. H. J.
Richards
Mr. G. F. Smith,
M.R.C.V.S.
Sir Richard Trehane,
B.Sc.
Milk
Marketing Board for Northern Ireland
104
Ministry of
Agriculture, Fisheries and Food
Represented
by Mr. G.H. C. Amos,
Mr.
Benynon, M.R.C.V.S., D.V.S.M.
Mr. E. H. Bott, C.B.E.
Mr. J. G. Carnochan,
Mr.
D. J. Drummond, M.R.C.V.S.
Mr. R. H. Ewart, M.R.C.V.S.
Mr. I. A. Graham, M.R.C.V.S.
Mr. S. A. Harris, B.Sc. (Agric.)
Mrs.
A. G. Hills,
Mr. M. E. Hugh Jones, M.A., Vet.M.B., M.PH.,
M.R.C.V.S.
Mr. E. Lowes, M.R.C.V.S.
Mr. W. T.
L. Neal, M.A., A.R.I.C.
Mr. W. G. Parkinson, B.V.Sc., M.R.C.V.S.
Mr. P. A. power, M.A.
Mr. J. Reid, C.B., M.R.C.V.S., D.V.S.M.
Mr.
T. Whyte Stobo, M.R.C.V.S.
*Ministry
of Agriculture for Northern Ireland
Represented by Mr. E. Conn, M.R.C.V.S.
Professor C. Dow, Ph.D., B.V.M.S., M.R.C.V.S.
Mr. J. M. C. Parke, B.A.
Ministry of Defence
*G. O. C.
Western Command
Represented by Major General P. B. Gillett, C.B.,
O.B.E.
Royal Armament Research and Development Establishment
Ministry of Housing and
Local Government
Ministry of
Technology
(1) Laboratory
of the Government Chemist
(2) Water
Pollution Research Laboratory
Morville and District
Agricultural Club, Shropshire
Nantwich
Young Farmers Club
National
Association of British Market Authorities
National
Association of Corn and Agricultural Merchants Ltd.
National
Association of Wholesale Meat Salesmen of Scotland
National
Federation of Anglers
National
Federation of Meat Traders Associations (Incorporated)-
Represented by Mr. W. Bloor, M.Inst.M.
Mr. L. Dennis, M.Inst.M.
Mr. K. J.
Forder, M.A.
Mr. F. D. Johnson, B.E.M., M.Inst.M.
Mr. J. Partington, M.Inst.M.
Mr. T. Tasker, M.Inst.M.
105
*National
cattle Breeders Association-
Represented by Mr. M. O. K. Day
Mr. A. Greenhalgh
Mr. C. H. R. Reeves, D.L.
Mr. N. E. Simper
Mr. J. A. Taylor
Lt. Col. J. M. Wood
*National
Farmers Unions of England and Wales, and Scotland-
Represented by Mr. P. R. Butcher, B.Sc.
Mr. G. A. Catchpole
Mr. T. J. Cowen, B.A., M.B.E.
England and Wales
Mr. T. B. Jones, J.P.
Major H. G. B. Knight, M.C.
Mr. J. Cameron
Mr. R. C. Stewart
Scotland
*National
Farmers Union (Cheshire County Branch)
Represented by Mr. F. W. Cureton, F.C.C.S., J.P.
Mr.
J. Richardson
National Farmers Union (Chester Branch)
National Farmers Union (Ellesmere, Press and Wem
Branches)
*National
Farmers Union (Flintshire County
Branch)
Represented by Mr. L. Price
*National
Farmers Union (Shropshire
County Branch)
Represented by Mr. W. R. Horrell
Mr. B. J. Whittingham
*National
Farmers Union (Staffordshire County Branch)---
Represented by Mr. W. Kenny
Mr. A. L. Stickland, M.B.E.
*National
Farmers Union
(Wales)
Represented by Mr. D. Lloyd
Col. W. H. Newton Young
National Federation of Womens
Institutes
National Hunt
Committee
*National
Sheep Breeders Association
Represented by Mr. R. E. Dowse, F.R.I.C.S.,
F.L.A.S.
National
Stud
*National Union of Agricultural
Workers
Represented by Mr. J.
Hockenhull
Mr. D.
F. Hodsdon, O.B.E.
Mr. G.
Neish, J.P.
North-Western British Friesian
Breeders Club
*Office
International des Epizooties-
Represented by Dr. G. A. Moosbrugger
106
Office
of HIGH commissioner for Canada
Peak
Park Planning Board
Pig Industry Development
Authority
Porcofram Ltd.
*Public
Health Laboratory Service
Represented by Dr. R. J. Henderson, M.D.
Sir James Howie, M.D., M.D.C.P.Path., F.R.C.P.
Dr. A. D. Macrae, M.D., M.C.Path., Dip.Bact.
Dr. T. M. Pollock, M.D., M.R.C.P.
Racecourse Association
Ltd.
Red Deer Commission
Road Haulage Association
Ltd.
*Royal
Agricultural Society of England
Represented by Sir Walter Burrell, C.B.E., T.D.,
D.L.
Mr. J. Cumber, B.Sc., J.P.
Mr. C. Dadd, M.A., Dip.Agric.
Lord Woolley, C.B.E.
*Royal
Association of British Dairy Farmers---
Represented by Mr. F. R. Francis
Mr. D. Gemmill, O.B.E.
Mr. H. C. Mills
Mr. J. A. Pasfield, O.B.E., M.R.C.V.S.
Lord Rowallan K.B.E., M.C., T.D., D.L.
Mr. P. G. Snell
*Royal
College of Veterinary Surgeons
Represented by Mr. T. A. M. Chambers, M.R.C.V.S.
Professor D. L. Hughes, Ph.D., F.R.C.V.S.,
Dip.Bact.
Professor E. G. White , D.Sc., Ph.D., F.R.C.V.S.
Mr. A. J. Wright, J.P., M.R.C.V.S.
*Royal
Highland and Agricultural Society of Scotland
Represented by Mr. R. Dunlop
Mr. J. K. M. Oliver
Mr. R. H. Watherston, C.B.E.
Mr. W. Young, C.B.E.
Royal Institution of Chartered
Surveyors
Royal Society for the Prevention of
Cruelty to Animals
*Royal
Veterinary College
Represented by Sir John Ritchie, C.B.,
B.Sc., D.V.Sc., LL.D.,D.V.S.M., F.R.S.E.
Royal Welsh Agricultural Society
Ltd.
Represented by Mr. I. G. Evans
Mr. J. A. George, F.C.C.S.
Mr. F. V. John, M.R.C.V.S., D.V.S.M.
Mr. A. T.
Morgan, M.R.C.V.S.
Mr. H. Richards
Mr. T. D. Steadman
The Hon. Neville Hill-Trevor
107
*Salop County
Council
Represented by Alderman Lt. Col. A. Heywood Lonsdale, M.C., J.P., D.L.
Mr. F. W. Ward,
O.B.E.
*Sausage and Meat Pie Manufacturers
Association─
Represented by Mr. G. I.
Banks
Mr. R. Brazen, A.C.I.S.
Mr.
A. F. Brobyn
Mr. D. S. Munro
Mr. H. Whittle
Scottish Landowners
Federation
Scottish Pig Producers
Federation
Scottish Milk Marketing
Board
Soil
Association
*
South American Freight Committee---
Represented by Mr. A. B. Barrio
Mr. K. V. Epstein
Mr. A. G. Gordon, B.A.
Mr. D. B. Johnson
Sir Derek Vestey, Bt.
Mr. H. Warburton
South-Western Farmers
Ltd.
Staffordshire County
Council
Traders Road Transport Association
Ltd.
Vanodine Ltd.
Veterinarians
Union
Wantage Rural District
Council
Messrs. E. W. Watts
*Welcome
Foundation Ltd.
Represented by Mr. A. A. Gray, M.C., B.A., B.Sc.
Mr. S. L. Hignett, B.Sc., F.R.C.V.S.
Mr. T. W. F. Pay, B.Sc., M.R.C.V.S.
Mr. A. Thomson, M.R.C.V.S.
Welsh office
*West
Mercia Constabulary
Represented by Chief Superintendent A. Nichol
Chief Constable Willison
Worcestershire County
Council
Wynstay and Montgomeryshire
Farmers Ltd.
Youth Hostels Association of
England and Wales
108
Private
Individuals
*Mrs. A. M. Allen,
N.D.D.
Mr. T. E.
Appleby
The Hon. Anthony Berry,
J.P., M.P.
Mr. J. J.
Bowes
Miss M. Brand,
M.A.
Mr. R. H. Bradley, B. Vet.
Med., M.R.C.V.S.
Mr. W.
Brock
Sir Evelyn Delves
Broughton
Mrs. J.
Burrows
Dr. H. M. E. Cardwell, M.
A., Ph. D.
Mr. E. G. Cawdrey
Dr. D. S. Dane, B.A., M.B.,
B.Chir., M.R.C.P., M.C.Path.
Mr. B. W.
Dawes
Mr. R. Dean,
LL.B.
Mr. D. J. B. Denny, B.
Vet.Med., M.R.C.V.S.
Mr. J.
Dickin
Mr. R. N.
Ellis
Dr. C. W. A. Emery, C.B.E.,
M.B., B.Ch.
Mr. M. I. Evans,
B.Sc.
Dr. P. R. C. Evans, G.M.,
J.P., M.D., F.R.C.P.
Mr. W. G.
Fair
Mr. W. B. Faull, B.Sc.,
M.R.C.V.S.
Lt. Col. A.
Forbes
*Mr. J. Fox, M.C.,
M.R.C.V.S.
Mrs. E. C.
Gibson
Mr. M. T. Greenwood, B.
Vet.Med., M.R.C.V.S.
Dr. P.H. Gregory, D.Sc.,
D.I.C., F.R.S.
Mr. J. N. Gripper, B.Sc.,
M.R.C.V.S., J.P.
Mr. W. E.
Grund
Mr. S. R.
Hart
Mr. F. A. Irving, B.Sc.,
D.P.A., F.A.P.H.I.
Mr. J. S.
Jones
Professor H. D. Kay, C.B.E.,
D.Sc., F.R.S.
The Rt. Hon. The Lord
Kenyon
Mr. A. J. C. Kerr,
M.A.
Mr. K. P.
Lea
Mr. A.
Lepeudry
Dr. H. R. Lillie, M.B.,
Ch.B., B.Sc., M.I.C.E.
Mrs. M.
Livesley
Mr. W. L. R. Mather,
M.H.C.I.
Mr. J. J.
Meier
Mr. J. H. Monie, M.B.H.U.,
M.I.P.I., M.B.S.D.
Mr. P. R.
Ord
The Hon. Richard
Parker
Mr. H. W.
Phillips
Mr. A. J. Proud, B.V.Sc.,
M.R.C.V.S.
Mr. G. W. Power, M. Eng.,
M.I.C.E.
Mr. G. K. Ridley,
F.L.A.S.
Mr. H. E. Ritchie, B.V.Sc.,
M.R.C.V.S.
Mr. R.
Roberts
Mrs. L. M.
Rutter
Mr. A.
Rosen
Mr. J.
Smith
Miss C.
Soames
109
Private
Individualscontinued
Mr. C. J. N.
Stanford
Mr. B. Keys Statham, B.Sc.
(Agric) N.D.A.
Mr. W. J.
Stopford
Professor W. J. Thomas,
M.Sc., M.A.
Dr. J. R. T. Turner, M.A.,
M.R.C.S., L.R.C.P., J.P.
Lt. Col. Sir Richard Verdin,
O.B.E., T.D., D.L., J.P.
Mr. G. C. Vickers, B.V.Sc.,
M.R.C.V.S.
Mr. W. O.
Wade
Mr. T. G. W.
Wiles
*Dr. A. J. Wilsdon, B.Sc.,Ph.D.,
M.R.C.V.S.
Mr. G. A.
Wright
Lt. Col. Sir Watkin
Williams-Wynn, B.V., J.P.
Foreign
Countries visited by the Committee, and Persons who gave
Evidence to
Them.
Europe
Denmark
Mr.
S. Anderson
Mr. V. Bugge
Mr. V. Hornslet
Dr.
E. Michelsen
Dr. C. Werdelin
Federal Republic of
Germany
Dr. W. Eckerskorn
Dr. Grissler
Herr
Rojahn
France Mr.
A. Cortez
Mr. L. Dhennen
Dr.
E. Matthieu
Mr. J.
Santamaria
The
Netherlands
Dr.
J. G. Van Bekkum
H. A. Van den Berg
Dr. K. G. Robijns
Mr. W. wagenvoort
Dr. J. VerVoon
South
America
Argentina
Sr. A. Reichart-Under
Secretary for
Agriculture and Livestock.
Dr. Jorge
Borsella, Director General
of Animal Health and a team of officials from the Argentine Ministry of
Agriculture, Animal Health Service, and S.E.L.S.A. (Animal Health Field
Service)
[Discussions
were also held with the Director and Officials of the laboratories
of
I.N.T.A.
(National Institute of Technology) and S.E.L.S.A. which the Committee visited,
and with local representative and officials of S.E.L.S.A. during visits to the
estancias of Sr. Jaun Harriet, Senora
Inchauspe and Sr. Eduardo
Pereda. The Committee also met Dr. Lius Firpo Miro, President of the Argentine
Rural Society and some of its members and members of A.A.C.R.E.A. (Argentine
Association of Regional Agricultural Experimental
Stations).]
110
Brazil
Dr. Jose Fredre de Faria, Federal chief
Veterinary Officer and a team of officials
from
the Federal Veterinary Service and
the
Brazilian Ministry of Agriculture; also
Federal veterinary officials stationed in
Porto
Alegre (Rio Grande do Sul)
Dr.
Jose Augusto Muller, Head of the Department of Animal Health for the State of
Rio Grande do Sul, and a team of officials from the Department and from State
Veterinary Service
Uruguay
Sr. Frick Davie, Minister of Agriculture
Sr. M.
Capurro, Under Secretary of
Livestock and Agriculture
Dr. de Freitas, chief Veterinary Official and
a team of officials from the Ministry of
Agriculture and the Veterinary Service
Pan
American Foot-and-
Dr.
Carlos A. Palacios, Director
Mouth Disease Center,
Dr. M. Fernandez
Rio de
Janiero
Dr. Lambardo
United
state
of America
Dr.
R. J. Anderson, Associate Administrator
of the U.S. agricultural
Research Service
and a team of officials from the
Service
Dr. J. Callis, Director of the Plum
Island
Animal
Disease Laboratory and a team of
officials
Dr. Shahan, past Director of the Laboratory
Countries
whose Governments submitted written evidence.
|
Argentina |
Malaysia
(West) |
|
Australia |
New
Zealand |
|
Austria |
Netherlands |
|
Belgium |
Nigeria |
|
Botswana |
Northern
Ireland |
|
Brazil |
Norway |
|
Canada |
Pakistan
(west) |
|
Ceylon |
Poland |
|
Chile |
Republic
of Ireland |
|
Cyprus |
Republic
of south Africa |
|
Czechoslovakia |
Singapore |
|
Denmark |
Sweden |
|
Finland |
Switzerland |
|
France |
Tanzania |
|
Federal
Republic of Germany |
Turkey |
|
Ghana |
U.S.A. |
|
Greece |
U.S.S.R. |
|
Italy |
Uruguay |
|
Kenya |
Zambia |
|
Malawi |
|
111
THE NATURE OF THE DISEASE
Memorandum Submitted by the Ministry of Agriculture,
Fisheries and Food
The Virus and its
Types
1.
Foot-and-Mouth disease (FMD) is the most contagious of all animal diseases. It
is caused by a filterable virus, that is to say an organism so small that it can
pass through the minute pores of a filter capable of holding back ordinary
bacteria. The virus of foot-and-mouth disease although too small to be seen
using an ordinary microscope is visible under the electron microscope.
2. FMD virus can be classified into
differing groups or types. This classification has been based on the result of
tests for immunity; animals which have recovered from infection with one type
are immune to that type but remain susceptible to other types. There are seven
major types classified as O, A, C,SAT.1, SAT.2, SAT.3 and Asia I. Lesser
differences within these groups are classified as sub-types, e.g. 01,
A22. To date more than fifty distinct sub-types have been recognized;
the immunological difference between the main types is absolute but between
sub-type strains within a type it is one of degree.
3.
As well as the immunological difference between different sub-types other
characteristics may show variation. Strains may differ in the ease with which
they spread from one animal to another and the severity of the disease in different species may also vary.
Some strains of virus will readily infect pigs but not necessarily cattle and
vice versa. Other strains affect both species readily. The power of survival of
the virus outside the animal and the degree of immunity that remains in the
recovered animal are also subject to variation.
Animals Subject to the
Disease
4.
Cattle, pigs, sheep, wild ruminants and hedgehogs are susceptible to natural
infection with foot-and-mouth disease virus. On the Continent wild deer have
been implicated as a reservoir of infection but in this country they have not
been shown to play any part in the spread of the disease. Hedgehogs when
affected are so crippled that they are only likely to be a factor in the
transmission of the disease over a small area. It has been shown however that if
a hedgehog is infected shortly before hibernation the virus may lay dormant
during that period and that when it awakes clinical disease may develop in about
4 days. Although this could be significant in that outbreaks might occur in an
area several months after eradication was believed to have been effected, there
is no evidence that this has occurred. Experimental work has shown that the
coypu is susceptible to the disease but to date there is no record of natural
infection in this species.
5. Naturally occurring disease has been
recorded in the brown rat. Infection is thought to have entered through
abrasions caused by fighting. It is not considered that infection in this
species plays a significant part in the transmission of the disease although
mechanically the rat could be of considerable importance in carrying the virus
from one farm to another. During the 1967/1968 episode, samples from ground
vermin were examined at Pirbright, and no evidence of infection was revealed.
Guinea pigs, hamsters, rabbits, cats, dogs, mice and domesticpoultry can be
infected artificially with the virus but natural infection has not been recorded
in these species.
6. Human beings have occasionally been
infected with the disease but such cases are extremely uncommon bearing in mind
the frequent exposure of farmers and others to the disease where infection is
widespread in the livestock population
Symptoms
7. The incubation period after natural
infection is usually between three and eight days but it can be shorter or may
extend to 14 days or longer.
112
8. The first noticeable symptoms of the
disease are dullness, depressed appetite and a rise in temperature. Associated
with the development of lesions in the mouth and on the feet there is an
increase in the secretion of saliva, which may hang in strings from the mouth,
and the sudden appearance of lameness. In cows the milk yield falls
considerably.
9. Lameness in a number of animals,
especially when present in more than one species cattle and sheep or pigs, for
example, should arouse the gravest suspicion. Salivation in a number of animals
or even in one animal should always be looked upon with suspicion and should
lead to examination of the mouth. In affected cattle salivation is very
frequently accompanied by a smacking or sucking sound which is a characteristic
symptom of the disease. Salivation may occur in sheep and pigs but is not nearly
so noticeable in these species. It is usually sudden lameness that first
attracts attention in pigs and sheep, but this symptom may escape the casual
observer as the animals are so foot sore that they remain lying down. Affected
cattle frequently shake their feet, as if trying to remove something from
between the clays. Sheep will normally rise and move away when approached; if
not it probably means that their feet are tender.
10. In goats the general condition of
the animal often remains unaltered. The animal may be dull and the
characteristic smacking of the lips may be seen but the appetite is often not
affected. Lameness is not always evident. The milk yield is reduced and abortion
of dead kids is a common feature.
11.
The lesions of the disease consist of vesicles (blisters), which, in the mouth,
appear on the tongue, cheeks, gums and on the dental pad. In pigs the snout is
often affected. Foot lesions are usually found around the coronet, at the
junction of the skin with the hoof, at the base of the supernumerary digits and
on the soft tissue between the clays. They are also commonly found on the teats
in females. Less commonly, they may be seen in the nostrils, around the muzzle,
inside the vagina and, in pigs, on the skin of the body. The vesicles vary in
size from a pin head or half a walnut or even much larger if coalescence of
adjacent vesicles has occurred. They are easily broken by handling. When broken,
a clear liquid flows out, the mucous membrane over the vesicle looks ragged and
the undersurface has a red or raw appearance, which afterwards becomes yellow.
On parts such as the dental pad, where the mucous membrane is dense, the
affected mucous membrane may be thickened, and may remain attached after the
vesicle is broken. On handling, this thickened portion of membrane comes away in
the form of leathery-looking tissue, leaving a raw surface. The foot lesions are
similar to those in the mouth, except that the covering is denser. The
inflammation in the feet may lead to shedding of the clays. This happens in the
later stages of the disease, but more commonly in sheep and pigs than in cattle.
Even in the earlier stages the horn can frequently be seen separating around the
coronet in a downward direction in sheep and pigs. When the teats are affected,
damage to the udder of a permanent nature may follow. Very young calves may die
from enteritis (inflammation of the bowel) without showing evidence of
vesication externally.
12.
In typical cases, symptoms and lesions are readily observed but when the
vesicles have ruptured pain decreases and the animal may commence to eat.
Occasionally the disease is manifested in a milder form, for instance, the only
symptom in sheep and pigs may be lameness. Unless a close watch is kept, this
may be overlooked, especially in sheep if footrot is also present in the flock,
and in pigs, if the animals are running on soft ground or in straw yards. Again,
in mild cases in store cattle, especially when on good clean pasture, the period
when the animals are showing typical symptoms may be so short that they may not
be noticed unless the animals are caught and examined.
13.
Animals usually recover from foot-and-mouth disease but the loss owing to
depreciation, loss of milk, or permanent damage, is considerable. Abortion may
occur and mortality may be heavy among very young animals. Many ewes and lambs
may be lost if an outbreak occurs during the lambing season. Some
outbreaks,
113
however,
are more virulent than others and, in a very virulent outbreak, a considerable
number of animals of any age may die.
Spread
of the Disease
14.
All parts of the body of an animals affected with foot-and-mouth disease are
infective, in particular the virus is present in great concentration in the
fluid of the vesicles and is also excreted in the saliva, milk, urine and
dung.
15.
Virus appears in the blood soon after infection, and all excretions including
the saliva, urine, milk, faeces and semen may be infected before the animal is
clinically ill and for a short period after the symptoms have disappeared.
Maximum infectivity occurs during the period when the vesicles are developing,
rupturing, and releasing the vesicular fluid. In the past it has been considered
that convalescent animals were infective for a limited period only, except
insofar as the virus might persist on the skin or hair: however, work since 1959
gives rise to the belief that some animals may carry the virus for several months after recovery from the
clinical disease.
16.
Experimental work at pirbright with virus isolated from field samples during the
1967/1968 epidemic suggests that cattle and sheep may be sources of infection
for periods up to five days and pigs up to ten days before clinical symptoms
appear. Whether this is a phenomenon due to a characteristic of this virus
remains to be proved. But in the past the slaughter policy has succeeded despite
the apparent advantage held by the virus.
17.
Animal usually pick up the virus by direct contact with an infected animal in
byres, pastures, markets, lairages or in transport vehicles. When an animal is
salivating, the threads or droplets of saliva (and such things as straw
contaminated thereby) may be blown a considerable distance by the wind and thus
reach other animals.
18.
Indirect contact is, however, of more far-reaching importance in the spread of
the disease and this is spread of the disease and this is linked with the fact
that the virus can survive for long periods outside the living animal. The
disease may be spread by the hands, boots or clothes of milkers or other
attendants. It may be carried considerable distances in farm produce wheather
used as feedingstuffs for animals or as packing material and it may be
disseminated through a contaminated water supply. The roads, loading docks,
etc., along which affected animals have passed and the wagons in which they have
travelled may remain infective for some time. Ground vermin and game, rats,
fowls, birds, cats, dogs, foxes and horses may act as mechanical carriers of
infection. Hedgehogs and occasionally rats may become infected and could,
therefore, also be direct transmitters of disease.
19. Milk from infected animals used for
feeding other stock may transmit infection, as may skimmed milk or whey. Of
equal importance infected milk may contaminate churns and milk lorries or
storage tanks at milk depots, which may in turn contaminate subsequent
consignments of milk or may contaminate churn washings commonly used for
feeding pigs.
20. The
virus is destroyed by heat, direct sunlight and certain disinfectants, but cold
and darkness favour its survival. Vesicular fluid dried rapidly on glass slides
at 37ΊC. is
often inactivated immediately, but when dried slowly at room
temperature
it may
survive for several months. Laboratory tests have shown that under suitable
conditions the virus can survive at least 14 days on wool, four weeks on cow
hair, 11 weeks on boot leather, 14 weeks on rubber boots and 15 weeks on hay.
Cold storage conditions in the meat trade also favour the survival of the virus.
The virus is destroyed by the acidity which develops in the muscular tissue
slaughtered carcases stored at normal temperature during the normal development
of rigor mortis (the setting of the carcase). If an infected carcase is chilled
or frozen immediately after slaughter the acidity does not develop the muscles
and hence the virus may retain its infectivity for some months. Furthermore
liver, kidney, tripe, bone marrow and lymph glands do not develop acidity, and
virus survival for periods up to 45 months have been recorded. If a susceptible
animal comes into contact with any part of such contaminated material or part of
an infected carcase it is likely to develop the disease.
114
ORIGIN OF THE 1967-68 FOOT-AND-MOUTH
DISEASE EPIDEMIC
Presented
to Parliament by the
Minister
of Agriculture, Fisheries and Food
By
Command of Her Majesty
March
1968
Cmnd.
3560
The original
outbreak
1.
The
first case in the present epidemic was reported on 25th October,
1967, on the premises of R.N. Ellis, Bryn Farm, Nantmawr, Shropshire. This was
the initial case in the epidemic. No subsequent case was confirmed in which
animals had evidence of earlier disease.
2.
A very
full inquiry has been made into the origin of the infection. I have considered
all the possible means by which food-and-mouth disease virus could have been
brought to this original case, including movements of animals and persons,
mechanical carriage by birds and wind, materials used on the farm, infection
remaining from sources in the United Kingdom, and imported
meat.
3.
Movements
of animals and persons.
There was no possibility that the disease was brought on to the farm in animals
because the only movement on to the farm was a boar which subsequent
investigation showed could not have brought to the disease. No one in the
household had been abroad and there had been no foreign visitors on the farm, so
that the possibility of the disease being introduced by human agency can be
disregarded.
4.
Mechanical
carriage by birds and wind. Infection in the past has reached the
Eastern and Southern parts of this country from Europe, possibly carried by
birds, when there have been epidemics in the countries across the English
Channel, but the food-and-mouth disease situation on the Continent has improved
greatly in 1967. Denmark and Holland have been clear since April; France has had
only 17 cases, the last occurring in early September in the Departments of
Correze in the southern part of Central France where it was eradicated by a
vigorous slaughter policy. It is true that Western Germany has experienced
serious epidemics in 1965 and 1966, and had over 3,000 cases in 1967, but I
consider the distance too great for the disease to have been brought from
Germany to Shropshire by birds, or by the wind. In any case, the prevailing
winds over the three weeks before the outbreak were such as to rule out
wind-borne infection.
5.
Materials
used on the form. The importation of hay and straw is
prohibited from dangerous sources; and no imported hay and straw had been used
on the farm.
6.
Infection
from sources in the United Kingdom. The last previous outbreak was in
Warwickshire. Infection was confined to four farms and the area was cleared on
29th September. It is impossible for infection to have remained
quiescent in the intervening period and in any case there were no movements of
animals between Warwickshire and Bryn Farm.
7.
In the
early days of October 1967 there was an escape of virus in an isolation compound
at the Animal Virus Research Institute, Pirbright. Due to a breakdown in the air
filtration system, infection escaped from one unit to another, a distance of
approximately 30-40 yards. This occurred in cool humid weather with strong
south-westerly winds, so that infection could not have been spread to the north
by this means. None of the workers from Pirbright went to the Oswestry district
at the material time, nor were any vehicles sent there. This incident cannot be
considered as the origin of the outbreak on Bryn Farm.
8.
Imported meat. My inquiries showed that the
only supplies of imported meat of any consequence distributed in the district at
the relevant time were frozen lamb from Australia, New Zealand and South
America. The first two are free from foot-and-mouth disease and can be
discounted. Inquiry has shown that
the butcher who supplies the Bryn Farm household purchased his supplies of
imported meat from the F.M.C. at Wrexham. He had received, as well as New
Zealand lamb, 113 carcases of frozen Argentine lamb.
9. Throughout October, both frozen lamb and
lamb bones for the dogs were supplied to Bryn Farm by this butcher. It has not
been possible to establish whether these supplies were of New Zealand or
Argentine origin.
10. Disease on Bryn Farm was confirmed in
pigs, two of which showed older lesions than the others. These were two gilts
which had been in the yard and in a field adjacent to the stockyard a week
before disease was reported. Cattle were not affected at the time of diagnosis
nor when the stock was slaughtered, so that the disease must have originated in
the pigs.
11. The owner did not feed swill to his
pigs, but bones were fed to his dogs
and could have been carried into the yard or neighbouring fields where
the gilts had been. In fact the veterinary officers responsible for slaughter
and burial of the animals saw bones in the yard at the farm. The owner stated
that bones were boiled and fed to the dogs but did not claim that this was
always done effectively.
12. It was not possible to establish
conclusively that imported frozen lamb carried foot-and-mouth disease virus to
the farm, but as other generally recognised sources of infection had been
eliminated, it remained the most probable vector.
Other cases in the
epidemic
13. Undoubtedly a majority of the subsequent
cases in the epidemic were the result of local spread by various means including
perhaps birds and the wind. However, a particularly worrying feature in the
first four weeks of the epidemic was the large number of cases which were
reported almost simultaneously over a wide area. There had been no movement of
animals, and stockowners were generally reporting their suspicions very soon
after clinical signs became apparent. This strongly suggested the possibility
that several primary cases occurred at about the same time. Here again there is
possible link with the imported frozen lamb carcases.
14. The carcases of Argentine lamb
received by the butcher who supplied Bryn Farm were part of a consignment of 770
frozen lamb carcases which had been despatched from Establishment 1408 in the
Argentine and arrived at Wrexham on 25th August. The remainder of
these 770 carcases were distributed over a wide area around Wrexham, including
deliveries to Ellesmere, Shrewsbury, Press, Market Drayton, Nantwich and
Chester. This is the area of a greatest concentration of infection in the first
four weeks of the epidemic. Becasuse these carcases had been distributed it was
not possible to takeweeks of the samples for examination. Samples were taken
from other lamb carcases from the Argentine and the results were
negative.
15. Other consignments of
lamb carcases from Establishment 1408 have been traced. The great weight of
distribution was in Nottingham, the West Midlands and London (which also
supplied lamb to the West Midlands); smaller quantities were, however, supplied
to the southampton-Portsmouth district, Bristol and South Wales, and
Newcastle.
16. At a subsequent stage in the epidemic
new unexplained foci of disease cropped up as far east as Lincoln and as far
south as Brandon, near Coventry, all during a period of a complete standstill on
animal movements. On some of these farms a connection has been established with
frozen lamb from Establishment 1408, but in no case is there strong evidence
that this lamb was responsible for the outbreak. Some examples are given in the
Appendix.
116
17.
Inquiries as to the possible origin of infection are continuing in two
outbreaks, and the distribution of the meat is being examined in areas where it
was sold, apparently without causing foot-and-mouth disease
infection.
18. The only type of virus isolated in
this epidemic was 01. It is known that this type of virus is present
in South America, but it has not been possible to ascertain the situation
regarding foot-and-mouth disease in sheep and the prevalent types of virus in
the area which supplies Establishment 1408. It is known from returns made by the
Argentine authorities that foot-and-mouth disease occurs in the exporting area
concerned but the returns do not distinguish between cattle and
sheep.
Conclusion
19. My
conclusions on the origin of the epidemic are:
(i) I have been unable to
discover any possible source of the infection
except Argentine lamb.
(ii) Although there is not
conclusive evidence that Argentine lamb was the
source, I am of the opinion that there is sufficient circumstantial
evidence
for
concluding that this lamb was the cause of the initial case on
Bryn
Farm
and some of the subsequent case
JOHN REID,
Chief Veterinary Officer
February, 1968.
117
APPENDIX
In the
six cases referred to below there were no infected premises within the usually
accepted distance for local spread.
D.F.474: A.
J. Bridewell & Sons,
Courteenhall, Northampton 21.11.67.
(Nearest outbreak 50
miles)
This farm did not receive imported meat.
It is situated a quarter of a mile from the village of Quinton. It is known that
the villagers were receiving meat for their households and bones for their dogs
from butchers whose wholesale suppliers had received frozen lamb from
Establishment 1408. Cattle in a field to which the villagers dogs had access
were affected.
D.F.9744:
Clarke, Carnforth, Lancashire
30.10.67
(Nearest outbreak over 80 miles)
This was regarded as a primary
outbreak. Argentine lamb probably from Establishment 1408 was received in
cardboard cartons by a school canteen at Carnforth in mid-October. The cartons
were disposed of at the local refuse tip. The tip is heavily scavenged by birds.
The infected Place is approximately 3 miles from the tip.
D.F.1696: Buxton, Penkridge,
Staffordshire
18.12.67
(Nearest outbreak 9 miles)
This
isolated outbreak was confirmed on 18th December. The cowman on this
farm has five dogs which have been fed on raw meat. The cowman obtained his
household supplies and meat for his dogs from sources which had received frozen
lamb from Establishment 1408. The dogs have access to pasture land on the
farm.
D.F.1740: Redfern, Little Eaton,
Derbyshire
20.12.67
(Nearest outbreak 7 miles)
Meat
supplies to the farmers household did not include imported material but at a
neighbouring bungalow adjacent to the field in which the infected animals were
grazing and in which the owner had four Alsatians, meat and bones were received
from a supplier who received frozen lamb from Establishment 1408. A bone was
found in the infected field, to which the dogs had
access.
D.F.1797: Wardrop, Hopwell,
Derbyshire
23.12.67. (Nearest outbreak 16
miles)
Meat
is purchased from a firm which received lamb from Establishment 1408. Household
refuse is disposed of on the premises and rats and dogs would have access to
it.
D.F.1929: Potter, Woodborough,
Nottinghamshire
1.1.68. (Nearest outbreak 16
miles)
The
meat supply to the house is not involved, but 2 miles from the farm there is a
bone transhipment depot accessible to birds, dogs and foxes. These bones are
collected from butchers shops which are known to have had imported meat,
including frozen lamb from Establishment 1408.
118
THE
1967/1968 EPIDEMIC
Distribution
of Outbreaks of Foot and Mouth Disease
In
Relation to Cattle Densities in N.A.A.S. Districts
119
120
Appendix
IV
Enclosure
C
121
122
SCOTLAND
Cattle Density Per
100 Acres
Of
Crops, Grass and Rough Grazing
In
Relation to Counties
123
LEGISLATION TO CONTROL THE
INTRODUCTION OF FOOT-AND-MOUTH
DISEASE
VIRUS INTO GREAT BRITAIN
CARCASE
MEAT AND OFFAL
1. The
Importation of Carcase and Animal Products Order, 1954,
as amended, sets out a number of countries(all of them free from Foot-and-Mouth
Disease) from whom all meat and meat products are admitted unconditionally
into Great Britain. These are
Australia
Canada
Falkland Islands
Finland
Iceland
Irish
Republic
Norway
New
Zealand
South
Africa was included in this list but was removed following an outbreak of Foot-and-Mouth Disease there in
December, 1967.
2. The
Order also controls imports from other countries:
(a)
Meat
Until
4th December, 1967,
when imports of fresh meat and offal were suspended from all countries other
than those from which supplies were admitted unconditionally (see paragraph 1
above), detailed veterinary requirements were set out in the Third Schedule
for
imports from a number of countries: imports from other countries were also
permitted under licences. When
the ban on imports was lifted on 15th April, 1968, the operation of
the Third Schedule remained suspended and all imports from countries other than
those listed in paragraph 1 are subject to licence. These licence specify
conditions designed to ensure insulation from disease
(i) For countries other than those in South
America
They include certification that
the farm of origin of the animals, and the slaughterhouse where they are
slaughtered, must be at least 20 km. (12½ miles) from any known outbreak of disease;
that the animals have had no contact with other animals from within such a 20
km. area; and that they should be subject to ante and post-mortem
inspection. These conditions are
varied somewhat for countries in Africa to take account of the different
conditions in those countries. For
example, in the Republic of South Africa the required distance from known
disease is stipulated at 40 miles rather than 20 km. (12½ miles) while in South
West Africa and Botswana the whole of the game-fenced and controlled compartment
from which the stock is drawn must be free fromdisease, and in the case of
Swaziland freedom of the whole country from disease is required. Licences are
available for imports from the following countries:-
124
Europe
Africa N.
America
Austria*
Botswana*
U.S.A.*§
Belgium
Republic of S. Africa
Cuba *
Bulgaria *
South West Africa *
(Costa
Rica *
Denmark
Swaziland*
under consideration)
France
Holland
Hungary*
Poland
Rumania*
Sweden
Switzerland*
Yugoslavia*
(Czechoslovakia*-
under construction)
Notes
* Beef only
Beef and mutton and lamb
Beef, mutton and lamb and pork
§ Pork under
special precautions solely for the United States Forces
(ii) Argentina, Brazil, Chile and
Uruguay
Beef and beef offal are
allowed into Great Britain from these countries subject to certification that
they come from frigorificos on an approved list drawn up by the Ministry of
Agriculture, Fisheries and Food. To
be on the approved list implies that a frigorifico meets with the requirements
of the Bledisloe arrangements which provide that the animals for slaughter
should come only from estancias free of Foot-and-Mouth Disease; that appropriate
disinfection procedures should be adopted during their transportation; that they
have received ante and post-mortem inspection and that the slaughterhouse should
be free from disease. In addition,
the Governments of these countries have agreed to require that foot-and-mouth
disease shall be compulsorily notifiable, that movements of stock shall be
prohibited from affected establish-ments and that meat for export to Great
Britain shall be derived solely from animals vaccinated against Foot-and-Mouth
Disease with inactivated vaccine of
a standard controlled by the Government Veterinary Service.
(b)
Bacon and Ham
Imports are allowed from a number of
European countries and also from Cyprus and the Republic of South Africa so long
as they are accompanied by a certificate of processing or are marked, in the
case of some countries, with the official stamp of that country. The Importation of Carcase and Animal
Products Order, 1954 would also permit the importation of bacon and ham on
similar terms from approved frigorificos in South America but, in fact, no trade
takes place.
(c) Dry Sausage
(Salami)
Sausage
casings
Imports are allowed
from a number of countries, subject to stringent animal health provisions
applied in the country of origin.
3. A
number of animal products, having regard to their mode of preparation and use,
present negligible animal disease risks and are admitted either unconditionally
(e.g. bone charcoal and steamed bone flour) or subject to certification of their
method of preparation (e.g. fellmongered goat and cow hair).
125
LIVESTOCK
4.
The Diseases of Animals Act, 1950 provides, with certain exceptions, that
all imported animals shall be slaughtered at the point of landing. (In practice
this provision is not operative as animals are no longer imported for slaughter
from
outside the British Isles.) The exceptions are for animals from
Ireland,Channel Islands and the Isle of Man, Canada and, subject to special
arrangement for quarantine and testing, for exhibition in Zoos; but animals may
occasionally be imported from other countries or for other purposes under
separate Orders made for each individual importation. To ensure that, so far as is
practicable, imported animals are disease-free the Orders provide for testing
the animals for presence of virus before embarkation, and quarantine both before
and after shipment. These
arrangements apply to such importations as pedigree animals coming from the
Commonwealth and animals brought in for exhibition or other exceptional purposes
such as breed improvement.
WRAPPING MATERIALS
5. The Importation of Meat etc.
(Wrapping Materials) Orders of 1932 and 1939 specify the only kind of
materials which may be used and the markings which must appear on them to
identify them as meat wrappings.
The use of these materials for any other purpose such
as packing feedingstuffs, bedding, fertilisers, agricultural and horticultural
produce is forbidden. Further, the
Foot-and-Mouth Disease
(Packing Materials) Order 1925, as amended, provides that
no animal in Great Britain should be brought into contact with boxes or wrapping
material used for wrapping meat or uncooked meat products.
HAY, STRAW, DRIED GRASS
6. The Importation of Hay, Straw and
Dried Grass Order, 1961 prohibits the importation of hay and straw except
from certain countries which are free from Foot-and-Mouth Disease unless it is
being used as packing material, forms part of a manufactured article, or is
licensed for other than animal use. When hay or straw has been used for packing
purposes it must be kept away from animals in Great Britain and should be
destroyed once used, unless it is to be used again as packing material. These
latter requirements are provided for in the Foot-and-Mouth Disease (Packing
Materials) Order of 1925.
SEMEN
7. The Importation of Animal Semen
Order, 1955 as amended, prohibits, except under licence, the importation of
semen of, among others, horses, sheep, goats and all other ruminating animals
(except cattle) into Great Britain.
A licence to import semen may lay down any conditions which Ministers may
think fit to impose for the purpose of preventing the introduction or spread of
disease.
8. The importation of cattle and pig
semen is controlled by the Agriculture (Mis-cellaneous Provisions) Act,
1943 under which licences are issued which again are subject to stringent
veterinary safeguards.
SERA AND GLANDULAR PRODUCTS
9. The use of sera and glandular
products in the treatment of cattle, sheep, goats, other ruminating animals or
swine is prohibited under the Foot-and-Mouth Disease (Sera and Glandular
Products) Order, 1939, unless the substance carries the authorisation of the
Minister.
THERAPEUTIC SUBSTANCES
10. The Diseases of Animals
(Therapeutic Substances)Order of 1952 prohibits, except under licence, the
manufacture or importation of therapeutic substances, including sera and
vaccines.
126
SWILL
11. The Diseases of Animals
(Waste Foods) Order, 1957 prohibits in general the
feeding to cattle, sheep, pigs, goats or poultry waste foods which
contain or have been in contact with anything that is part of a carcase unless
the food has been boiled for at least one hour. Under the provisions of the Order it is
an offence to allow any of the above named animals access to unboiled food
waste. Local authorities are required to licence swill boiling plants and to
subject them to inspection. There
is an exception to this licensing rule for small farmers, i.e., with less than 4
pigs and 50 poultry.
PASSENGER AND VEHICULAR TRAFFIC
12. There is at present no permanent
legislative control over the movement of people into or within Great
Britain. During an outbreak of
Foot-and-Mouth Disease the provisions of the Diseases of Animals Act,
1950 could be used in exceptional circumstances to impose movement
restrictions within Great Britain if these were considered necessary to prevent
the spread of disease. For example,
during the 1967/1968 epidemic the Minister of Agriculture made the
Foot-and-Mouth Disease (Temporary Restrictions) Order, 1967 which
authorised the prohibition by notice in writing of entry by people onto
agricultural or adjoining land. This was a temporary Order which was
subsequently revoked. There are
however certain restrictions on vehicles used for ferrying livestock to and from
the Continent. Under the
Transit
of Animals (Amendment) Order, 1931 it is obligatory to clean and
disinfect a vehicle that has carried animals after use and before carrying other
animals.
127
APPENDIX VI
SUMMARY OF THE BLEDISLOE AGREEMENT, 1928
Article 1. No cattle, sheep or pigs
shall be slaughtered unless accompanied by a veterinary certificate of soundness
in accordance with the prescribed conditions.
Article 2. No animals will be moved
from the place of origin unless the livestock on that establishment have had
veterinary inspection and been found free from contagious disease, and that the
stock to be removed shall have been found healthy not more than two days before
removal.
Article 3. The wagons or other
transport shall be cleaned and disinfected by the transporting companies.
Article 4. Persons concerned with
forwarding livestock shall notify Government authorities in time for examination
before despatch.
Article 5. Animals sold through
markets shall be subjected to special examination in addition to examination at
the place of origin.
Article 6. Herds brought in on
foot shall comply so far as possible with similar conditions.
Article 7. All animals shall be
inspected ante and post-mortem and the consign-ment shall be rejected if
foot-and-mouth disease is found.
Article 8 and 9. In the event of disease, the yards where
animals have been shall be specially cleaned and disinfected.
Article 10. All meat wrappings
shall be new.
Article 11. Concerns salaries and
staff.
Article 12. Provides for
punishment of contraventions.
128
APPENDIX VII
SUMMARY OF CONDITIONS CURRENTLY APPLICABLE FOR THE
EXPORT OF BEEF AND BEEF OFFAL FROM ARGENTINA,
BRAZIL,
CHILE AND URUGUAY
1. Foot-and-mouth disease must be
compulsorily notifiable by owners of stock.
2.
If foot-and-mouth disease is confirmed movement of all susceptible
species from the affected establishment (e.g. estancia) must be prohibited for
at least 30 days after the detection of the last clinical case, subject to a
minimum standstill period of 60 days.
3. Any
animal intended for slaughter for export to the U.K. (in the form of carcase
meat, offal or meat products) must have been vaccinated against foot-and-mouth
disease at least twice at an interval of not more than six months; the last
vaccination to have taken place not more than 4 months and not less than 15 days
before slaughter. All vaccination
to be with inactivated vaccine controlled for innocuity and potency by the
Government Veterinary Service.
4. No animals to be loaded into vehicles
which have not been properly cleansed and disinfected .
5. All markets and fairs to be inspected
by Government Veterinarians. If foot-and-mouth disease is found no
affected animal or animal in contact with any affected animal to be allowed to
go to frigorificos approved for the export of meat or meat products to the
UK.
6. Lairage facilities at approved
frigorificos to be adequate and capable of being thoroughly cleansed. Thorough cleansing to be carried out
before the entry of each troup of animals.
Facilities to include accommodation for the isolation of any diseased or
suspect animal.
7. Ante mortem inspection by Government
Veterinarian and any sick animals
(from whatever cause) to be segregated immediately. If foot-and-mouth disease is found or
suspected no carcase meat or offal to be exported to the U.K. from any animal in
the troup and the pens to be thoroughly cleansed and disinfected after removal
of the animals.
8. Post mortem examination of
all export production under the direct supervision of a Government
Veterinarian. If foot-and-mouth
disease is found or suspected, carcases and offal of affected animals and of all
those animals in contact before slaughter or during slaughter and dressing to be
excluded from export to U.K. Thorough cleansing of facilities to be carried out
before production for export
to U.K. is resumed.
9. Packings, coverings and
wrappings of meat and offal intended for export to the U.K. to be entirely
new.
APPENDIX
VIII
UNITED KINGDOM
IMPORTS OF CARCASE MEAT AND OFFAL
|
Fresh
Beef
Irish Republic .. .. ..
..
Other Countries .. .. ..
..
Total
..
..
..
Chilled
Beef
Rhodesia
..
..
..
Australia
..
..
..
New Zealand ..
..
..
Other Commonwealth
Countries
Irish Republic ..
..
..
Sweden
..
..
..
Hungary
..
..
..
Yugoslavia ..
..
..
Republic of South
Africa
..
Brazil
..
..
..
Uruguay ..
..
..
Argentine Republic ..
..
Other Foreign Countries
..
Total
..
..
Frozen Beef
Basutoland
..
..
..
Botswana
..
..
..
Swaziland
..
.. ..
Rhodesia
..
..
..
Australia ..
..
..
New Zealand
..
..
..
Other Commonwealth
Countries
Irish Republic ..
..
..
Sweden
..
..
..
Norway
..
..
..
Netherlands
..
..
..
Yugoslavia
..
..
..
Republic of South Africa ..
..
U.S.A
..
..
..
Brazil
..
..
..
Uruguay
..
..
..
Argentine Republic ..
..
..
South West Africa ..
..
..
Other Foreign Countries ..
.. |
Quantity 000
tons
|
|
1962
20.3
|
1963
17.4
|
1964
16.5
0.8 |
1965
25.8
|
1966
35.1
|
1967
94.6
0.6 |
1968
78.7
11.2 |
|
20.3 |
17.4 |
17.3 |
25.9 |
35.2 |
95.2 |
89.9 |
|
4.7
1.7
0.3
0.6
0.7
1.0
0.4
34.1
0.7
1.2
10.3 157.9
... |
4.7
__
__
__
0.1
0.8
0.1
12.3
0.4
1.9
26.3
201.3
0.1 |
3.3
0.3
0.7
__
0.2
__
13.0
1.3
0.2
20.27
128.7
0.2 |
3.7
0.1
0.7
__
0.2
__
5.5
1.1
0.1
2.8
95.3
1.6 |
__
0.1
0.1
__
1.6
0.1
__
3.4
0.9
0.8
6.9
108.7
1.0 |
__
__
.
__
9.3
__
0.2
...
0.2
4.1
88.0
1.8 |
__
__
.
__
6.8
0.4
__
17.8
1.9
13.0
15.2
4.3 |
|
213.6 |
247.9 |
168.6 |
111.1 |
123.6 |
103.7 |
59.4 |
|
5.2
3.3
31.3
6.2
0.6
2.1
0.2
0.7
5.1
2.2
0.3
0.1
6.8
23.6
|
6.6
3.1
17.0
1.9
0.1
0.5
3.4
0.7
0.7
2.3
2.4
0.3
0.5
14.6
34.2
|
5.5
1.7
81.6
24.6
0.1
3.2
0.1
.
0.6
0.4
1.1
1.2
0.8
11.1
20.7
0.2 |
9.1
1.6
88.7
28.3
0.1
2.3
...
0.6
0.2
2.1
0.5
0.2
1.5
13.0
0.3
|
9.9
66.5
18.7
0.1
4.1
0.3
0.3
0.3
8.0
0.3
0.5
3.2
9.6
1.9
0.1
|
3.7
0.8
18.3
8.6
0.1
4.1
0.2
0.2
0.4
0.3
4.9
0.4
0.1
4.6
13.4
1.6
6.7 |
2.7
0.4
24.5
9.3
1.2
4.7
0.9
1.5
9.5
1.6
1.6
2.8
11.3
19.1
0.9
14.2 |
|
TOTAL
..
..
.. |
87.6 |
88.1 |
152.9 |
148.5 |
124.0 |
68.5 |
106.2 |
Note: The entries in these
Tables are rounded figures and small quantities (shown as...) are omitted from
the entries against countries. For these reasons the totals are not the sum of
the entries for countries.
UNITED
KINGDOM Ύ
continued
|
Veal
Australia
. .
. .
. .
New Zealand
. .
. .
. .
Other
Commonwealth
Countries
. .
. .
. .
Denmark
. . .
. .
.
Netherlands
. . .
. . .
Other Foreign
Countries
. .
|
Quantity 000 tons
|
|
|
1962
1.8
1.0
0.1
0.1
3.0
0.1 |
1963
1.2
0.2
-
0.1
2.6
|
1
1964
2.7
0.8
-
0.4
2.1
0.1 |
1965
1.8
0.4
-
0.3
2.2
|
1966
1.2
0.3
0.7
0.6
0.1 |
1967
0.4
0.2
-
0.9
0.2
0.1 |
1968
0.4
0.1
-
0.5
0.2
0.2 |
|
|
|
Total
. .
. . .
.
All Beef and Veal
Basutoland
. .
. . . .
Botswana
. . . .
.
.
Swaziland
. .
. . .
.
Rhodesia
. .
. . . .
Australia
. .
. .
. .
New Zealand
. .
. .
. .
Other
Commonwealth
Countries
..
. . .
.
Irish Republic
. .
. . .
.
Sweden .
.
. .
. .
. .
Norway
. .
. .
. .
. .
Denmark . . . .
. .
.
.
Netherlands
. .
. .
. .
Yugoslavia
. .
. .
. .
Republic of South
Africa
. .
U.S.A.
. .
. .
. .
. .
Brazil
. .
. .
. . .
.
Uruguay
. .
. .
. . .
.
Argentine
Republic
. .
. .
South West Africa
. . .
.
Rumania
. .
. .
. .
. .
Poland
. .
. .
. .
. .
France
. .
. . .
. .
.
Iceland
. .
. .
. . . .
Other Foreign Countries
. . |
6.1
5.9
7.9
34.9
7.5
21.6
3.1
0.2
0.2
3.7
39.2
2.9
0.3
1.3
17.2
181.5
0.4
|
4.
2
-
6.6
7.7
18.2
2.1
0.1
19.0
4.2
0.7
0.1
3.2
14.6
2.8
0.3
2.5
40.9
235.5
-
-
-
-
0.2
|
6.2
-
5.5
5.1
84.7
26.1
0.1
19.9
0.1
0.4
2.7
13.5
2.4
1.2
1.0
31.8
149.4
-
-
0.1
0.9
-
0.1
|
4.7
-
9.1
5.3
90.6
29.2
0.1
28.4
0.3
3.0
5.7
3.2
0.5
0.3
4.2
108.3
0.3
1.4
-
|
2.8
-
9.9
-
67.7
19.1
0.1
40.9
0.3
-
0.7
0.9
3.7
8.9
0.4
1.3
10.1
118.4
1.9
0.1
0.9
0.2
|
1.8
-
3.7
0.8
-
18.7
8.8
0.1
108.0
0.2
0.2
1.4
0.7
0.5
5.0
0.5
0.3
8.6
101.4
1.6
5.1
1.5
0.7
0.6
0.6
|
1.4
-
2.7
0.4
-
24.9
9.4
1.2
90.3
1.6
-
4.6
1.8
27.3
1.6
1.6
4.7
24.3
34.4
0.9
3.6
3.9
13.9
0.2
3.5
|
|
|
Total
. .
. .
. . |
327.6 |
357.6 |
345.0 |
290.1 |
285.5 |
269.0 |
256.9 |
|
=small
quantities
131
UNITED
KINGDOM Ύ
continued
|
Mutton
Australia
..
..
..
New Zealand
..
..
..
Canada
..
..
..
Other
Commonwealth
Countries ..
..
..
Irish Republic
..
..
..
Iceland
..
..
..
U.S.A.
..
..
..
Uruguay
..
..
..
Argentine Republic ..
..
..
Other Foreign Countries
..
Total
..
..
..
Lamb
Australia
..
..
..
New Zealand
..
..
..
Other Commonwealth ..
..
..
Countries
..
..
..
Irish Republic
..
..
..
Iceland
..
..
..
Netherlands
..
..
..
U.S.A.
..
..
..
Chile
..
..
..
Uruguay
..
..
..
Argentine Republic
..
..
Other Foreign Countries
..
Total
..
..
..
Pork
Australia
..
..
..
New Zealand
..
..
..
Other Commonwealth
Countries
..
.. ..
Irish Republic
..
..
..
Sweden
..
..
..
..
Norway
..
..
..
Denmark
..
..
..
Netherlands
..
..
..
Yugoslavia
..
..
..
Republic of South
Africa
..
..
Argentine Republic
..
..
Finland
..
..
..
Other Foreign Countries
..
|
Quantity 000 tons |
|
1962
7.9
35.2
-
-
0.2
-
-
0.1
|
1963
6.1
25.3
-
-
0.2
-
0.2
0.1
0.1
|
1964
8.1
27.2
-
-
0.2
0.3
|
1965
8.9
28.0
-
-
0.1
0.1
0.6
0.6
|
1966
3.7
12.4
-
-
0.5
0.7
-
|
1967
4.8
20.2
-
-
0.3
0.4
-
0.3
|
1968
7.0
32.3
0.8
-
0.1
0.1
2.1
-
-
|
|
43.4 |
32.0 |
35.8 |
38.3 |
17.3 |
26.0 |
42.5 |
|
14.4
256.7
13.2
2.5
0.1
0.9
-
21.0
0.1
|
16.6
257.3
0.1
10.9
2.1
0.3
0.9
0.3
21.8
0.2
|
14.4
265.9
-
8.9
1.2
-
0.3
0.3
-
11.9
0.2 |
14.1
266.5
9.2
1.0
0.2
0.8
0.8
14.2
|
6.7
258.7
11.2
0.7
0.2
0.5
0.2
20.0
|
4.5
276.6
-
9.8
2.8
-
0.7
18.1
0.1 |
9.4
285.1
-
6.0
3.6
-
0.1
-
-
-
|
|
308.3 |
310.4 |
303.1 |
306.7 |
298.3 |
312.7 |
304.3 |
|
0.7
8.4
4.7
0.3
0.4
1.9
3.1
0.3
|
-
0.4
0.1
7.8
0.6
0.2
0.5
1.6
0.1
-
-
|
-
0.3
0.3
5.6
0.7
-
0.2
0.1
2.3
-
-
|
0.8
16.4
1.1
0.3
0.2
0.1
1.5
0.1
-
|
-
0.1
0.3
5.8
1.8
-
0.1
1.0
1.1
-
0.2 |
-
0.1
0.4
2.3
0.9
-
0.2
0.3
0.5
-
6.1
|
-
0.3
0.2
8.2
1.6
-
1.7
-
-
0.4
-
5.6
|
|
Total
..
..
..
|
19.8 |
11.3 |
9.7 |
20.6 |
10.3 |
10.9 |
18.0 |
=small
quantities
UNITED
KINGDOM Ύ
continued
|
Beef and Veal
Offal
Basutoland
..
..
..
Botswana
..
..
..
Swaziland
..
..
..
Rhodesia
..
..
..
Australia
..
..
..
New Zealand
..
..
..
Canada
..
..
..
Other
Commonwealth
Countries
..
..
..
Irish Republic
..
..
..
Sweden
..
..
..
..
Denmark
..
..
..
Netherlands ..
..
..
Yugoslavia
..
..
..
U.S.A.
..
..
..
Brazil
..
..
..
Uruguay
..
..
..
Argentine Republic
..
..
..
Republic of South
Africa
..
Other Foreign Countries
..
Total
..
..
..
Mutton and Lamb Offal
Australia
..
..
..
New Zealand
..
..
..
Canada
..
..
..
Other
Commonwealth
..
Countries
..
..
..
Irish Republic..
..
..
Iceland
..
..
..
..
Netherlands
..
..
..
U.S.A.
..
..
..
..
Chile..
..
..
..
Argentine
Republic
..
..
Other Foreign
Countries
..
..
|
Quantity 000 tons
|
|
1962
0.2
0.5
10.4
3.4
1.6
-
2.8
0.4
1.4
0.5
0.8
10.7
0.5
0.5
10.7
0.1 |
1963
-
0.3
0.5
10.9
4.2
1.9
2.2
0.4
1.4
0.9
0.8
8.6
0.4
0.4
18.1
0.1
|
1964
-
0.2
0.4
12.2
4.6
3.3
1.7
0.4
1.3
0.2
0.4
15.3
0.9
0.4
12.4
0.1 |
1965
-
0.5
0.2
12.3
4.0
4.4
1.9
0.4
1.3
0.8
0.1
18.2
0.9
0.3
9.6
0.2 |
1966
-
0.6
-
11.7
4.1
3.8
2.4
0.4
0.9
0.5
0.2
17.2
0.5
0.2
9.7
0.3
0.4 |
1967
-
0.3
-
8.4
4.5
2.5
4.7
0.4
1.9
0.3
0.1
15.7
0.3
0.7
10.2
0.1
0.2
|
1968
-
0.1
-
-
10.0
6.6
3.7
-
4.8
0.4
1.5
0.2
0.1
18.2
0.5
0.8
6.2
0.2 |
|
44.4 |
51.2 |
53.8 |
55.0 |
52.9 |
50.2 |
53.1 |
|
4.3
13.3
0.1
-
0.8
0.3
0.2
3.9
0.1
1.1
0.1
|
4.4
13.3
0.1
0.8
0.3
0.2
4.0
0.8
1.5
0.1 |
4.3
14.7
0.1
-
0.8
0.3
0.1
4.9
0.1
1.2
0.1
|
4.4
15.2
0.1
-
0.6
0.2
0.2
5.2
0.1
1.7
0.2 |
6.0
15.6
-
0.7
0.4
5.0
0.1
2.1
0.2
|
5.3
19.0
0.7
0.4
0.1
4.5
0.2
2.2
0.1 |
6.8
20.6
-
0.6
0.4
4.3
-
-
|
|
Total
..
..
.. |
24.1 |
25.5 |
26.5 |
27.8 |
30.2 |
32.5 |
32.8 |
=small
quantities
133
UNITED
KINGDOM Ύ
continued
|
Pork
Offal
Australia
..
..
New Zealand ..
..
Canada ..
..
Other Commonwealth
Countries
..
..
Irish Republic ..
..
Sweden
..
..
Denmark
..
..
Netherlands
..
..
Yugoslavia
..
..
Republic of South Africa
Argentine Republic
..
Other Foreign Countries
Total ..
..
Total
all Carcase Meat and
Offal
Basutoland..
..
..
Botswana
..
..
Swaziland
..
..
Rhodesia
.. ..
Australia
..
..
New Zealand
..
..
Canada
..
..
Other Commonwealth
Countries
..
..
Irish Republic
..
..
Sweden
..
..
Norway
..
..
Iceland
..
..
Denmark
..
..
.
Netherlands
..
.
Hungary
..
.
Yugoslavia
..
..
Republic of South
Africa
U.S.A
..
..
..
Chile
..
..
Brazil
.. ..
Uruguay
..
Argentine Republic
Finland
..
France
..
..
Poland
..
..
Belgium
..
..
Rumania
..
..
.
South West Africa
Other Foreign Countries
|
Quantity 000 tons |
|
|
|
1962
0.3
0.3
1.6
2.7
0.4
8.8
1.4
0.6
0.1
|
1963
0.3
0.3
2.4
2.3
0.3
9.7
0.6
0.5
0.1
-
|
1964
0.2
0.4
3.4
2.7
0.4
11.6
0.4
0.4
0.1
0.1 |
1965
0.2
0.4
3.4
-
3.1
0.4
14.7
0.4
0.3
0.1
0.5 |
1966
0.2
0.4
3.1
-
2.9
0.4
12.2
0.1
0.1
0.1
0.2 |
1967
0.2
0.3
3.4
-
2.6
0.4
13.2
0.1
-
0.2 |
1968
0.1
0.3
5.0
-
3.1
0.9
14.1
-
-
0.1
-
0.2 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
16.3 |
16.5 |
19.7 |
23.6 |
19.6 |
20.6 |
23.8 |
|
|
6.1
8.4
72.2
316.5
3.3
49.6
8.6
0.5
2.8
10.8
7.6
0.4
43.6
3.3
15.1
0.9
1.8
17.7
214.4
-
-
-
|
-
6.9
8.3
56.5
302.9
4.6
0.1
42.2
5.4
0.7
2.5
11.5
5.3
0.1
17.6
3.2
13.5
1.8
2.9
41.7
277.0
-
-
-
-
|
-
5.7
5.5
124.0
339.2
7.3
40.0
1.6
0.1
1.5
13.6
3.5
16.6
2.7
22.0
0.4
1.9
32.2
175.0
1.0
0.1
0.1
-
|
-
9.6
5.6
130.5
344.1
8.0
|