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 MAJESTY’S 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 Committee’s 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
|
I.- |
1 – 2 | |
|
II.- |
FOOT-AND-MOUTH
DISEASE AND ITS EPIDEMIOLOGY
|
|
|
|
(a) The
Disease |
3 - 8 |
|
|
(b) Epidemiology
|
9 – 45 |
|
III.- |
46 – 54 | |
|
IV.- |
FOOT-AND-MOUTH
DISEASE IN GREAT BRITIAN
|
|
|
|
(a)General
|
55 – 56 |
|
|
57 – 63 | |
|
V.- |
64 – 71 | |
|
|
(a)
Origin
|
72 – 82 |
|
|
(b) Spread
|
83 – 96 |
|
|
(c) Costs |
97-101 |
|
VI.- |
PREVENTION
AND CONTROL OF FOOT-AND-MOUTH DISEASE |
|
|
|
102-124 | |
|
|
(b)
In
Great Britain
|
125-136 |
|
VII.- |
DISCUSSION
OF FUTURE POLICIES FOR GREAT BRITAIN |
|
|
|
(a) Import
Policy |
137-172 |
|
|
(b) Slaughter
Policy |
173-175 |
|
|
|
176-211 |
|
|
212 | |
|
|
(e)Research |
213-215 |
|
VIII.- |
|
216-222 |
|
|
|
|
|
|
|
Pages |
|
|
97-100 |
5
TABLES
Page
6
FIGURES
Page
MAPS
PHOTOGRAPHS
|
17-23 |
7
APPENDICES
|
I.- |
List
of those giving Written and Oral Evidence |
101-111 |
|
II.- |
Description
of Foot-and-Mouth Disease |
112-114 |
|
III.- |
Cmnd
3560-“Report on the Origin of the 1967/1968
Foot-and- Mouth
Disease Epidemic” (White Paper) |
115-118 |
|
IV.- |
Maps
Relating to Cattle Density- |
|
|
|
A.
Distribution
of Outbreaks of Foot-and-Mouth Disease
|
119 |
|
|
120 | |
|
|
121 | |
|
|
122 | |
|
|
123 | |
|
V.- |
Legislation
to Control the Introduction of Foot-and-Mouth Disease
Virus into Great Britain |
124-127 |
|
VI.- |
The
1928 Bledisloe Arrangements |
128 |
|
VII.- |
Summary
of Conditions Currently Applicable for the Export
of Beef
and Beef Offal from Argentina, Brazil, Chile and Uruguay |
129 |
|
VIII.- |
Imports
of Carcase Meat and Offal into the United Kingdom
1962- |
130-135 |
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
FOOT–AND -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).
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 abroad> 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 immigrant’s 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 < 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 steer’s tongue , and shows the ragged apperance of the
broken “ skin ” ; two pieces of “ skin ” have been removed and laid on the
animal’s 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
pig’s 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
Oceania
51.
Foot-and-mouth disease has never been known in New Zealand.
Australia has been free of the disease since 1872.
Asia and the Sub-Continent
of Asia
52. In large areas of South-East Asia and the Sub-Continent of Asia foot- and-mouth disease is endemic. We have no precise information about the disease in China but Japan has been free since 1933. In the Middle East sporadic disease occurs from time to time and the disease is endemic in certain areas.
U.S.S.R.,
Central and South-East Europe
53. Foot-and-mouth disease is reported to
be sporadic in European U.S.S.R. but endemic in the cattle raising areas of
Central Asia. It is said to be present in wild animals in these areas and in
adjoining countries. Outbreaks occur from time to time in the Balkans and in
Central Europe and may at times
give rise to epidemics. The disease appeared in Rumania in 1959 and spread to
the neighbouring countries of Bulgaria, Yugoslavia and Hungary. About the same
time outbreaks occurred in Poland and Finland. By 1960 Rumania and Bulgaria,
and by 1961 Yugoslavia, were once again free of the disease but sporadic
outbreaks have occurred since. By agreement with Czechoslovakia, Poland and
Rumania, the U.S.S.R. maintains buffer zones of vaccinated along its frontiers
with these countries and in some areas zones about nine miles wide are kept
free from all susceptible livestock for additional security. Bulgaria
continues to vaccinate in its border area adjoining Turkey as part of the
campaign to protect south-eastern Europe against types of virus from which
Europe is generally free. (In paragraph 121 we describe the measures that
were
taken from 1962 onwards to fight the spread into Europe of South African type SAT. 1
virus and of type A22 virus which spread through Turkey and the Anatolian
Peninsula as far as Greece.)
Western
Europe
54. Table III gives the incidence of
foot-and-mouth disease from 1954 to 1968 in the European countries
nearest to Great Britain. Outbreaks in Great Britain are also shown, for the
purpose of comparison. Luxembourg Northern Ireland, Norway and the Republic of
Ireland have had long periods of complete freedom from the disease. In the
remaining countries mentioned in the table, outbreaks of the disease have
occurred regularly in most years, and during some periods a number of countries
such as France, the Federal Republic of Germany, Italy, Portugal and
Spain have suffered heavy attacks. Among more distant countries not
included in the table, Finland has been free since 1959 and Sweden since 1966.
The disease has never been introduced into Vaccination has been used to control outbreaks of the disease in some European countries since about 1939, and by 1960 countries such as France and the
Netherlands had developed and were applying general pro- phylactic vaccination programmes.
These programmes, together with the
slaughter policy, have greatly reduced the general level of infection
in Western Europe over the last few years. This is especially evident in
France where there was a steep fall in the number of the outbreaks after
1961.
33
TABLE III
Incidence of Foot-and-Mouth Disease in some European Countries,
1954-1968
|
Austria..
.. Belgium
..
.. Denmark
..
.. Federal
Republic of Germany ..
.. France
..
.. Italy ..
..
.. Luxembourg ..
.. Netherlands ..
.. Northern
Ireland
.. Norway
..
.. Portugal
..
.. Republic
of Ireland
.. Spain ..
..
.. Switzerland ..
.. Great
Britain ..
.. |
1954 |
1955 |
1956 |
1957 |
1958 |
1959 |
1960 |
1961 |
1962 |
1963 |
1964 |
1965 |
1966 |
1967 |
1968 |
|
0 700
43
481 838 6,450
4
34 0
0
3 0
5,189*
5 12 |
0 195
43
257 2,451 12,635
0
48
0
0
0
0 924*
3 9
|
37 693
6 1,401 6,800 5,890
18
47
0 0
41
0 9,254*
121 162
|
108
328
45 6,383 99,424 7,394
2
40
0
0
37
0 17,839*
111
184 |
0
568
11
1,265
14,127
6,453
0
11
0
0
3,912
0 226,597*
53
116 |
6
57
1
118 6,188 11,764
0
6
0
0 1,489
0 89,191*
13
45 |
1
180 1 1,395 7,382 11,547
0
3
0
0
53
0 11,259*
96
298 |
0
121
22 6,989 2,626 18,272
0
179
0
0
1
0
21
141
103 |
0
6
0 11,359
199 5,237
0 5,470
0
0
0
0
0
133
5 |
59
67
23 7,700
28 5,114
6 2,103
0
0
0
0
3 144
0 |
0
2 4 5,342
56 12,372
0
146
0
0 2,018
0 5,607
68
0 |
34
112
2 15,944
10 5,842
0 1,426
0
0
770
0 1,303
671
|