This manual mainly addresses the situation where FMD invades a country, or a zone within a country, which was formerly considered free from FMD. Should such an emergency occur, all initiatives would be directed at rapid containment of the disease to the primary focus or zone of infection, and eradication within the shortest possible time to avoid spread and possible progression to an endemic status.
However, the strategies enunciated may also be used by FMD endemic countries to help them plan better control programmes and progressively to eradicate the disease.
Countries should aim towards a goal of verifiable eradication, which will enable a documented case to be presented for international (OIE) recognition of national or zonal freedom (with or without vaccination).
There are a number of epidemiological and other factors that influence the control and eradication strategies selected for FMD. These include the following.
There is no cross-immunity among the seven serotypes of the FMD virus. Within the serotypes, there is a spectrum of antigenic variation that may lead to reduced immunity.
FMD is one of the most contagious of epidemic livestock diseases and can spread very rapidly. Early warning is therefore essential to detect an incursion while it is still localized. Early and decisive reaction is required if the disease is to be contained and eventually eliminated without serious socio-economic consequences. To be effective, the control measures must be applied in the shortest possible time, since action within hours, never mind days, is crucial to success.
Pigs are important amplifying hosts for the disease, cattle are regarded as good indicator hosts, whereas sheep tend to show few clinical signs and are often considered maintenance hosts for a relatively short period where movement and transport can be responsible for virus spread.
Humans are not susceptible to FMD infection, but often transmit the virus mechanically.
Infected animals may excrete the virus for up to a few days before exhibiting clinical signs.
A proportion of recovered cattle, African buffaloes and sheep remain virus carriers for variable periods.
Wild or feral ruminant or porcine animal populations may act as reservoirs for infection.
Direct contact between animals is the most significant method of transmission, but the virus may persist for considerable periods in the environment (particularly in temperate climates) and mechanical transmission by fomites is also considerable.
The FMD virus may persist for long periods in certain meat and dairy products, and swill feeding of these to pigs is another significant method of transmission, especially in the international and intercontinental spread of the disease.
Windborne spread over considerable distances is possible in temperate climates. Local airborne spread may also occur in many environments. Computer modelling can to some extent predict this spread, which may be useful for zoning and surveillance purposes.
In hotter climates, direct contact is by far the most significant method of transmission and an understanding of livestock movement and trading patterns is vital for the framing of FMD control and eradication strategies.
Inactivated vaccines are widely used for FMD, but vaccine strains must be carefully matched to prevailing field virus strains if a satisfactory level of protection is to be attained; vaccination cover must attain a level of at least 80 percent for effectiveness; and good census information is essential to verify true coverage percentages.
Some virus strains have a higher predilection for one or another livestock species (e.g. pigs or cattle), which has significant implications for the planning of vaccination campaigns.
The immunity afforded by vaccines does not last long. Vaccination and revaccination campaigns need to be carefully targeted, comprehensive and consistently applied.
A proportion of vaccinated animals can become subclinically infected if they are subsequently exposed to the homologous virus and may be able to transmit infection for up to 14 days after vaccination, even when they become immune to the development of clinical disease.
Serological tests that allow discrimination between antibodies resulting from infection and vaccination (NSP ELISA tests) are now becoming available and should permit more accurate monitoring of control and eradication programmes based on mass vaccination.
Stamping out usually leads to more rapid eradication of FMD than vaccination but in the short term is very expensive and resource intensive. Apart from strictly veterinary considerations, public perceptions and environmental concerns must be taken into account. Combined strategies are very useful in many circumstances.
The basic principles that can be applied to the control and eradication of FMD are:
Denial of access of the virus to susceptible host animals
- through import controls and quarantine, including control of animals in transit;
- through good hygiene and sanitary practices; removing potentially contaminated materials from the environment by cleaning, disinfection and/or safe destruction; and preventing the feeding of contaminated materials to livestock.
Avoiding contact between infected and susceptible animals
- through zoning, quarantine of infected or potentially infected farms or areas, livestock movement controls and perhaps the erection of fencing or other physical barriers.
Reducing the number of infected or potentially infected animals in livestock populations
- through slaughter of infected or potentially infected animals and safe disposal of their carcasses by deep burial or burning or (preferably) rendering.
Reducing the number of susceptible animals
- through destocking and/or comprehensive vaccination programmes.
The strategy chosen is likely to be a combination of some or all of these approaches. There is no single FMD eradication strategy that is perfect or even appropriate for all circumstances. The emphasis given to the various methods in devising FMD control and eradication strategies will depend on epidemiological factors, livestock husbandry systems, community acceptance and likely cost.
A stamping-out policy will probably be most appropriate for countries with highly developed livestock industries, particularly for those with a substantial actual or potential export trade in livestock and livestock products to protect. In the latter context the downtime from loss of national FMD-free status and inability to export, is likely to be less, not only because eradication may be achieved more quickly by stamping out, but also because there is a subsequently shorter period before an international declaration of FMD freedom can be made and accepted. While large-scale stamping-out campaigns are extremely expensive and resource intensive in the short term, they may be outweighed by overall lower production and trade losses.
Stamping out is a viable proposition if an outbreak can be detected early while still reasonably localized and contained by quarantine and livestock movement controls. An essential prerequisite is that good epidemiological capabilities exist, which allow the locations and extent of the infected areas to be rapidly and accurately determined. This involves not only good disease surveillance, but also livestock identification systems that facilitate traceback and traceforward of possibly infected animals.
Countries that plan a stamping-out policy should also have a fall-back position. They should have a vaccination plan, which can be applied if the rate of FMD spread gets out of hand and outstrips the resources for stamping out. Ring vaccination, targeted blanket vaccination or suppressive (dampening-down) vaccination in selected areas can be applied to decrease the rate of spread of virus infection. Vaccination can also be used for intractable foci of infection. A decision can be made later as to whether it is desirable to slaughter vaccinated animals to get a declaration of FMD freedom for trade purposes more quickly.
For most countries, large-scale stamping out is not a viable option. In these cases emphasis must be given to targeted vaccination campaigns, supported where possible by livestock movement controls and judicious stamping out. Eradication can be achieved in this way if done systematically.
Zoning is the proclamation of geographic areas in which specific disease control actions are to be carried out. These areas are usually in the form of concentric "circles" around known or suspected foci of infection, with the most intensive disease control activities in the inner zones. Zoning is one of the early actions to be taken when there is an incursion of FMD in a country. The actual size and shape of the zones may be determined by administrative boundaries or geographic barriers, or be driven by epidemiological or resource imperatives. However, because the spread of FMD is mainly by means of movement of infected animals, animal products or contaminated materials, it is very important not to lose sight of the fact that transmission can occur over hundreds or thousands of kilometres by road or air overnight. It would therefore be shortsighted during an epizootic to depend upon the declaration of infected zones to contain the disease, unless there is a high level of confidence that the movement of livestock or other dangerous materials, such as meat, from infected to free zones can be prevented by geographic barriers or instituted control measures. Experience has shown that the establishment of an effective cordon sanitaire in many countries is far from simple and that such measures are easily evaded. It is certain that poorly organized farms distant from the zone of infection may be at greater risk than well-managed commercial farms within the infected zone.
The infected zone encompasses the area immediately surrounding one or more infected farms, premises or villages. While its size and shape are influenced by topographical features, physical barriers, administrative borders, epidemiological considerations (including the likelihood and possible direction of windborne spread), this zone is generally recommended to be at least a 10-km radius around disease foci in areas with intense livestock raising and 50 km in areas where extensive livestock raising is practised.
The size and shape of the infected zone(s) are also influenced by the type of disease control activities to be carried out. If intensive stamping out is planned it could be desirable for the size of the infected zone to be at the minimal end of the spectrum. If, on the other hand, zoning is to be used as the basis for planning vaccination campaigns, the infected zone(s) may be larger.
In the initial stages of an outbreak, when the extent of the infected zone is not well known, it would be prudent to declare larger infected zones (and even an all-inclusive national zone), impose movement restrictions accordingly, and then progressively reduce them when active disease surveillance reveals the true extent of the outbreak.
The surveillance zone is larger than the infected zone it surrounds and can also include more than one infected zone. It acts as a buffer zone between infected and FMD-free zones. Known livestock movement patterns should be taken into account when defining surveillance zones, which may cover a whole province or administrative region and, in some cases, the whole country.
These zones encompass the rest of the country. However, because of the potential of FMD for wide dissemination, it would be unwise to regard any part of a country in the throes of a new outbreak as not requiring a high level of surveillance. The emphasis in free zones should be on strict quarantine measures to prevent entry of the disease from infected zones and continuing surveillance to provide confidence of continuing freedom. These zones should be subjected to the same degree of information dissemination as the zones in which the outbreak occurs. This information should be extended, through good and rapid communication, to neighbouring countries.
Eradication of FMD by stamping out is only likely to be successful if a number of prerequisites are in place, which will require careful advanced planning.
ESSENTIAL PREREQUISITES FOR AN FMD STAMPING-OUT CAMPAIGN
It is essential that farmers and other people who have had their livestock slaughtered or property seized should be fairly compensated at current market value. This compensation should be paid without delay. Valuation for compensation purposes should be undertaken by experienced, independent valuers. Alternatively, generic valuation figures could be agreed upon for specific categories of livestock. At least the market value of the animals should be paid. Under some circumstances, replacement of stock may be offered in lieu of monetary compensation. If replacement of stock after a suitable period is considered to be a better alternative than cash compensation, this should be confirmed in consultation with livestock owners.
Failure to pay adequate and timely compensation will seriously compromise FMD eradication campaigns by causing re sent ment in communities and a lack of cooperation and will act as a spur for the illegal smuggling and clandestine sale of animals from infected areas to avoid losses.
A stamping-out campaign should not be contemplated unless there are adequate provisions for compensation.
A quick assessment needs to be undertaken by the Consultative Committee on Emergency Animal Diseases (CCEAD) (see Chapter 7, Vaccination campaigns in an endemic situation) at the time of an FMD incursion, taking into account all the factors mentioned above, together with a review of the extent of the outbreak and other epidemiological factors, before a stamping-out campaign is initiated. Contingency planning should identify the trigger factors to activate a vaccination campaign.
Actions to be taken in infected zones
The overall aims in the infected zone are twofold, to:
prevent the further spread of infection through quarantine and livestock movement controls; and
remove the sources of infection rapidly, through slaughter of potentially infected animals, safe disposal of carcasses and decontamination procedures.
Disease surveillance and other epidemiological investigations.
Trained veterinary officers or inspection teams undertake intensive active surveillance for FMD, with frequent clinical examination of herds and flocks. These officers or teams should wear protective clothing and practise good personal decontamination procedures to prevent taking infection to the next farm they inspect.
At the same time, traceback and traceforward investigations are carried out whenever an infected herd is found. Tracing back determines the origin of any new cattle, pigs, sheep or goats that had been brought on to the infected premises in the three weeks before the first clinical FMD cases (and which may have been the source of infection) and then the farms in question are inspected. Tracing forward determines the destination of animals that have left the infected premises prior to or after the first clinical cases. All farms that may have become infected by these animals are then inspected. However, traceback and traceforward investigations quickly become complicated if animals have transited through livestock markets.
Tracing should include all animal movements as well as the movement of vehicles and personnel concerned with feed lorries, milk tankers, animal dealers, and so on.
Farms that are impeccably managed (accredited) within the infected zone can be treated as if they were a small island of a surveillance zone (see section below). Caution must be exercised in determining this status as expensive or attractive structures, facilities or animals are sometimes misinterpreted as good management.
Quarantine of infected and dangerous contact premises. These premises are epidemiological entities where animals have become infected - whether a single farm or household or an entire village or settlement, or even a livestock market or abattoir. Dangerous contact premises are those for which there are reasonable epidemiological grounds to suspect that they have become infected, even though the disease is not yet clinically apparent. The infection may be caused by close proximity with infected farms; mingling of animals; movement of people, vehicles, equipment, materials, etc.
All infected and dangerous contact premises should be immediately quarantined with a ban on the exit of live animals, meat and dairy products and other potentially contaminated materials, pending further disease control action (see section below). Vehicles and other equipment should be disinfected before leaving the premises, paying particular attention to the interior transport compartment of vehicles used for the transport of live animals.
Movement controls. It is essential to impose a complete ban on the movement of live susceptible animal species and animal products within and out of the infected zone. Great care is required to ensure that neither animals nor animal products are smuggled out of the zone. Because of the high risk that they constitute for spread of infection, livestock markets and abattoirs should be closed.
It may be necessary to set up control points or roadblocks at exit points from the infected area(s) to prevent unauthorized movements.
Slaughter of infected and potentially infected livestock. All susceptible livestock species in infected and dangerous contact premises, or in a larger area if this is deemed necessary, are immediately slaughtered, whether they are obviously diseased or not. Owners should be asked to collect and confine their animals the day before the slaughter team arrives. The animals should be slaughtered by methods that take account of animal welfare concerns and the safety of operatives. Means of animal restraint (crushes, sedative drugs and means for their application, etc. may be required). Rifles or captive bolt guns are most commonly used for the culling of livestock. Captive bolt pistols should be used in confined areas where there is danger of ricochets. Use of a captive bolt should take into account the fact that the animal may be stunned and not necessarily killed, and appropriate measures taken to ensure that the animal is dead before burial or burning. Rifles should be used only by competent and experienced marksmen to avoid threatening the safety of people and non-target animals. Lethal injections (e.g. barbiturates) may also be used if practical.
In cases where animals are poorly confined or are allowed to scavenge in the surrounding countryside, it may be necessary to send out special teams to locate and shoot animals, using trained marksmen.
Reference should be made to the Manual on procedures for disease eradication by stamping out, FAO Animal Health Manual No. 12 (FAO, 2001) for more information on slaughter procedures.
Safe disposal of carcasses. This is the disposal of carcasses of all animals that have either been slaughtered or have died naturally of FMD, where the carcasses no longer constitute a risk of further spread of the pathogen to other susceptible animals either by direct or indirect means, e.g. by carrion eaters or scavengers or by contamination of food or water. Carcasses should be disposed of as quickly as possible (preferably within 24 hours). This is most usually done by deep burial covered by quicklime (depending on factors such as the nature of the terrain, closeness of water tables to the surface, and availability of earth-moving equipment) or by burning (depending on the availability of suitable fuels and the danger of starting grass or bush fires) or by rendering. Where rendering is used, the live animals and/or carcasses should be transported in leakproof vehicles. If in situ disposal is not practical it may be possible to transport carcasses to a common disposal point in these sealed vehicles. This should be done within the infected zone wherever possible. Reference should be made to the Manual on procedures for disease eradication by stamping out, cited in the section above, for more information on disposal procedures.
Decontamination. This involves the thorough cleaning and disinfection of the environs of infected premises, with particular attention to where animals have congregated, including animal houses, sheds, pens, yards, water troughs, and so on. Potentially contaminated materials such as manure, bedding, straw and feedstuffs should be removed and disposed of in the same way as for carcasses. It may also be simpler to burn very poorly constructed pens, for example. Preliminary thorough cleaning should be undertaken with copious water to which soaps and detergents may be added. Appropriate disinfectants for FMD include sodium hydroxide (2 percent w/v in water), sodium carbonate (4 percent w/v in water) and citric acid (0.2 percent w/v). Sodium carbonate is preferred to sodium hydroxide as it is less corrosive. New commercial disinfectants have recently become available that are less corrosive or less environmentally harmful (contact EMPRES for further details).
Reference should be made to the FAO Manual on procedures for disease eradication by stamping out, cited above, for more information on decontamination procedures.
Destocking period. After slaughter, disposal and decontamination procedures have been completed, the premises are left destocked for a period, determined by the estimated survival time of the pathogen in the particular environment. As a general rule, this time is shorter in hot climates than in cold or temperate climates. However, a minimum of 30 days is recommended.
Actions to be taken in surveillance zones
The following disease control actions should be undertaken in surveillance zones.
Active disease surveillance for FMD should be enhanced. Susceptible species livestock in the zones should be inspected at about weekly intervals and their owners questioned about disease occurrences and livestock movements, etc. Any sick animals should be thoroughly investigated, including dispatch of diagnostic samples to the laboratory. The burden of this surveillance could be alleviated if it were practicable for some of the work to be delegated to the informed and trained farmers themselves.
Movements of susceptible animal species and products from infected zones should be banned. Movement from surveillance to free zones may be allowed but only after health inspection and the issue of an official permit.
Abattoirs, dairy factories and other risk enterprises could be allowed to operate but only when subjected to strictly enforced zoosanitary codes of practice.
Sales of live animals, meat and dairy products can continue unless it is considered that they constitute a threat for the further spread of the disease. Sales should be subjected to record-keeping, surveillance and rigidly enforced codes of practice, including the official issue of movement permits.
Pen-side tests that determine the state of infection could be applied in movements.
Actions to be taken in disease-free zones
The emphasis in FMD-free zones is on preventing entry of the disease and accumulating internationally acceptable evidence that the zones are indeed FMD free (see section on International collaboration on p. 57).
The entry of pigs or pig products from infected zones should be banned and only allowed subject to official permits from surveillance zones. Well-managed (accredited) farms within infected zones could be treated as if they were surveillance zones.
At the completion of the agreed destocking period, livestock may be reintroduced to previously infected farms or villages. Livestock used for repopulation must come from known FMD-free zones or countries and should preferably be certified infection free by means of not only clinical inspection but also serological testing. However, this should only be done if there is reasonable certainty that these farms/villages will not be reinfected from external or internal sources. Restocking at full capacity should only take place after sentinel animals have been introduced on each previously infected farm and observed closely for three to four weeks. The animals should be tested serologically with samples taken at the beginning (day 0) and at day 21 or day 28, to ensure they stay free of FMD before full repopulation. Intermittent sampling may also be performed. After repopulation, intense active surveillance for the disease should be maintained in the area at least until international declarations of freedom can be made.
FMD vaccination is, unfortunately, still carried out in a haphazard manner in many countries, resulting in the disease remaining endemic for long periods. It is far preferable for vaccination programmes to be carefully planned and then systematically implemented to achieve specific goals.
In cases where FMD has been introduced into a previously free country or region, an emergency vaccination campaign supplemented by other disease control methods may be used with the goal of eradication within a reasonably short time frame. Alternatively, in an endemic country, vaccination programmes may be planned to develop FMD-free zones progressively and eventually achieve national freedom.
Selection and supply of vaccines. Safe and potent inactivated vaccines, prepared using primary inactivating agents such as binary ethyleneimine, should be used. They should contain at least 3 PD 50 (protective dose for 50 percent of animals) and have a rated storage life of at least 12 months when stored at the correct temperature. The vaccine may be multivalent but should contain only the required serotypes and strains for the country. For emergency vaccination in the face of an epidemic, vaccine should be at least double the normal minimum potency (i.e. at least 6 PD 50).
ESSENTIAL PREREQUISITES FOR FMD VACCINATION PROGRAMMES
Pigs require FMD oily adjuvant vaccines, since they do not respond immunologically to the aqueous FMD (aluminium hydroxide-saponin) vaccines that are used for ruminants. Oil vaccines generate longer protection but are more expensive than aqueous ones, especially if a double-oil emulsion (water/oil/water) is used.
FMD vaccines should only be sourced from reliable manufacturers that conform to the OIE Manual of standards for diagnostic tests and vaccines (OIE, 2000). Supply of adequate quantities of FMD vaccine in an emergency may present a problem; countries therefore may consider it desirable either to join an international vaccine bank or make advance contractual arrangements with a reliable vaccine manufacturer.
Vaccination should follow the manufacturer's instructions.
Vaccination procedures. The target livestock species for vaccination are generally cattle, water buffaloes, sheep, goats and pigs. One or other of these species should only be excluded from vaccination programmes if there is strong epidemiological evidence that they have little involvement in the outbreak(s). Other species (e.g. camelids) are seldom included in vaccination programmes.
During visits by vaccination teams to livestock farming communities it may be desirable to combine FMD vaccination with other vaccination, such as for haemorrhagic septicaemia, contagious bovine pleuropneumonia, sheep and goat pox. This will conserve resources and may also help to achieve a higher level of farmer cooperation in the FMD programme.
Vaccination teams should be well trained and adequately equipped with transport, injecting equipment (and the means for sterilizing it), cold-chain transportation, animal restraining equipment, recording forms, protective clothing and disinfectant.
Sites should be selected that will allow animals to be properly restrained so that vaccine can be carefully injected subcutaneously or intramuscularly, according to the manufacturer's instructions.
Animal identification. Ideally, there should be a compulsory registration system for livestock and their vaccination. Failing this, they should be identified by ear tagging, ear notching or other means that will confirm that they have been vaccinated and when.
Emergency FMD vaccination campaigns
These cover situations where FMD has been introduced into a previously free country or area in a country and where stamping out alone is not considered to be a viable option.
Comprehensive emergency vaccination programmes supported by other disease control measures. Zones are defined and proclaimed as recommended in the section on Zoning on p. 42. The infected zone(s) become the target area for an intensive vaccination campaign, encompassing not only the known infected farms/livestock farming communities but also those areas thought to be at high risk of infection. Known livestock movement and trading routes along which the disease may spread should be taken into account, as well as the natural geographic barriers and administrative areas of zone boundaries, together with epidemiological factors. Movement of susceptible species livestock and their products out of the infected zone should be banned. Unvaccinated animals should not be brought into the zone. Movement of animals within the zone may be allowed, although it is highly desirable that known infected farms be quarantined.
Comprehensive (or "blanket") vaccination is carried out as quickly as possible within the target area. All susceptible livestock within the population should be vaccinated. FMD vaccination is safe for pregnant animals.
Practical experience in a number of countries has demonstrated that the spread of FMD can be very quickly halted by an emergency vaccination campaign using a single round of vaccination, providing that a potent vaccine (6 PD 50 or higher) is used, and all or nearly all susceptible animals are immunized.
In order to reduce the possibility of accidental spread of the disease:
different vaccination teams should deal with herds suspected or known to be infected with FMD and other herds to be vaccinated in the area;
operatives should be aware of the clinical signs of FMD and the immediate measures to be taken if the disease is encountered during vaccination;
vaccination teams should disinfect between locations;
equipment should be frequently sterilized and always sterilized between farms;
partly used vaccine containers should be discarded between farms and the amount discarded recorded;
different herds should not be congregated or mixed for vaccination;
in communities where many families own few animals, it is better to visit each family farm individually rather than congregate all the animals of a village.
Poorly implemented vaccination campaigns in which either poor-quality or inappropriate antigenic strain vaccines are used or only part of the target livestock population is immunized will probably result in slow and uneven spread of infection (a "smouldering" outbreak), which will be difficult to detect in surveillance programmes, and will increase the probability of endemicity.
A high level of disease surveillance activity should be maintained within the infected (vaccination) zone to detect any viral activity. Clinical surveillance may be supplemented by serological surveys to monitor the immune level in the population. The results of such surveys will become easier to interpret when tests that are able to discriminate between antibodies resulting from natural infection and vaccination become widely used.
Vaccination and, if so decided, the slaughter of infected and contact animals should be continued until either the clinical disease disappears from the target area or drops to such a low level that it can be tackled by other methods (e.g. stamping out). This may require two or more vaccination cycles, ensuring that excellent vaccine coverage is accomplished each time.
A surveillance zone should be maintained around the infected (vaccination) zone (see section on Zoning on p. 42).
Emergency ring (or buffer) vaccination. This involves the rapid creation of an immune belt around an infected zone. It may be done to contain a very rapidly spreading disease outbreak or in situations where the effectiveness of other methods to prevent the spread of the disease in and around infected zones, e.g. quarantine and livestock movement controls, cannot be guaranteed, or where these areas may be relatively inaccessible. A decision to implement ring vaccination needs to be made quickly or else the size and number of infected areas may make it impractical. The width of the immune belt should be determined by epidemiological factors and resource availability considerations but, as a general guide, should be of the order of 20-50 km. Speed is of the essence and vaccination in the target ring should ideally be completed in the shortest time possible (i.e. seven days). It is far preferable to select a narrower ring for which human resources, vaccines and other resources are available for comprehensive vaccination within this time frame rather than select a larger ring where gaps may be left in the immune belt for longer periods. The vaccination ring can be extended later when vaccination brigades have gained experience and become more efficient after the first phase. Having selected the target area for the ring, vaccination should commence at the outer circumference and move centripetally towards the infected herds or flocks. Separate vaccination teams should be used for herds/flocks in which infection is highly suspected. Ring vaccination will only prevent spread of infection if strict movement control is maintained from the infected area.
An immune belt can also be created, for example, along a border when there is an extremely high threat of entry of FMD and little else can be done to prevent it. In this case, depending on geographic and epidemiological considerations, an immune vaccinated belt of the order of about 50 km is reasonable. Every effort should be made to prevent animals moving through the immune belt. Immune belts should not be maintained over long periods when the threat has reverted to a low level.
This situation greatly complicates responses to FMD outbreaks. The potential or actual role of wild or feral animals as reservoir or maintenance hosts for FMD needs to be assessed epidemiologically in partnership with wildlife authorities.
Reduction programmes for susceptible wild or feral animals may be possible in infected areas. However, in the case of wildlife, it is very probable that these will be precluded on ecological or environmental grounds. If attempted, care must be taken to ensure that such programmes do not simply act to disperse potentially infected animals to new areas. In any event, attempts to control or reduce wild animal populations are only justified if there is good evidence that they are involved in the transmission of infection to wild animals - a relatively uncommon situation.
It may be possible to limit contact between susceptible wild and domestic animals and thereby reduce the chances of transfer of infection from one to the other. This could be done by double fencing, livestock-free buffer zones or removing livestock from epidemiologically important wildlife.
If none of these measures is likely to be practicable and/or successful, it will probably be necessary to mount ring or blanket vaccination programmes for livestock in those areas where infection in wildlife constitutes a continuing threat for disease in livestock.
Surveillance activities should be extended to wild and feral animal populations, in collaboration with wildlife authorities.
Public awareness and education campaigns should be seen as integral and important elements of disease eradication campaigns and crucial for their success. These campaigns should be mainly (although not exclusively) targeted at rural and peri-urban communities that will be affected by the disease and FMD control actions. The most appropriate means of getting the message across to specific communities should be used, such as radio broadcasts and village meetings. The latter are particularly suitable since they give people the opportunity to ask questions and material (such as pamphlets and posters) can be disseminated that will reinforce the information given.
Campaigns should inform people of the nature of the disease and what to do if they see suspect cases; what they can and cannot do during the eradication campaign and why; and the benefits of getting rid of FMD. Campaigns should emphasize that FMD control primarily benefits livestock producers and not the government.
Public awareness material that is targeted specifically at all stakeholders should be prepared. As well as the above groups, material should be prepared for politicians, senior bureaucrats and the press. There may also need to be a publicity campaign directed at consumers to reduce unnecessary buyer resistance to animal products, based on perceived public health risks.
OIE specifies requirements for recognition of national FMD freedom with and without vaccination, together with zonal freedom with and without vaccination. The following is extracted from the OIE International animal health code: mammals, birds and bees (10th edition, 2001). It should be noted that, since these OIE requirements are subject to periodic changes, it is very important to consult the latest version.
FMD-free country where vaccination is not practised. To be listed in FMD-free countries where vaccination is not practised, a country should:
have a record of regular and prompt animal disease reporting;
send a declaration to OIE that there has been no outbreak of FMD and no vaccination carried out for at least 12 months, with documented evidence that an effective system of surveillance is in operation and that all regulatory measures for the prevention and control of FMD have been implemented;
not have imported animals vaccinated against FMD since the cessation of vaccination.
The name of the country will be included in the list only after acceptance of evidence submitted by OIE.
FMD-free country where vaccination is practised. To be listed in FMD-free countries where vaccination is practised, a country should:
have a record of regular and prompt animal disease reporting;
send a declaration to OIE that there has been no outbreak of FMD for the past two years, with documented evidence that:
- an effective system of disease surveillance is in operation and that all regulatory measures for the prevention and control of FMD have been implemented; and
- routine vaccination is carried out for the purpose of the prevention of FMD; the vaccine used complies with the standards described in the Code; and there is a system of intensive and frequent surveillance for detection of any viral activity.
If an FMD-free country where vaccination is practised wishes to change its status to an FMD-free country where vaccination is not practised, a waiting period of 12 months after vaccination has ceased is required.
FMD-free zone where vaccination is not practised. An FMD-free zone where vaccination is not practised can be established in an FMD-free country where vaccination is practised or in a country where parts are still infected; and in countries with a surveillance zone, or physical or geographic barriers and animal health measures that effectively prevent the entry of the virus. A country in which an FMD-free zone where vaccination is not practised is to be established should:
have a record of regular and prompt animal disease reporting;
send a declaration to OIE that it wishes to establish an FMD-free zone where vaccination is not practised, where there has been no outbreak of FMD for the past two years, where no vaccination has been carried out for the past 12 months, and where no vaccinated animal has been introduced into the zone since the cessation of vaccination;
supply documented evidence that an effective system of surveillance is in operation in the FMD-free zone where vaccination is not practised as well as the surveillance zone, if applicable;
describe in detail:
- the boundaries of the FMD-free zone, and the surveillance zone, where vaccination is not practised;
- the system for preventing the entry of the virus into the FMD-free zone, and supply evidence that this is properly supervised and that all regulatory measures for the prevention and control of FMD have been implemented;
have a system of intensive and frequent surveillance for detection of any viral activity in the FMD-free zone where vaccination is practised.
The name of the free zone will be included in the list of FMD-free zones where vaccination is not practised only after acceptance of submitted evidence by OIE.
The name of the free zone will be included in the list of FMD-free zones where vaccination is practised only after acceptance of submitted evidence by OIE.
If a country that has an FMD-free zone where vaccination is practised wishes to change the status of the zone to an FMD-free zone where vaccination is not practised, a waiting period of 12 months after vaccination has ceased is required.
Very considerable mutual benefits can be derived through countries cooperating in their emergency animal disease preparedness planning. This applies particularly to neighbouring countries or countries within the same geographic region. Since such countries often have similar socio-economic, environmental, epidemiological and agricultural production profiles, they are also likely to have similar livestock disease risks and needs for and approaches to preparedness planning.
Countries in this situation may well consider pooling resources in their emergency animal disease preparedness planning. This may be done through informal networking or, more formally, through existing regional organizations such as Panaftosa in Latin America; the African Union/Interafrican Bureau for Animal Resources (AU/IBAR) in Africa; OIE, the Animal Production and Health Commission for Asia and the Pacific (APHCA) and the Association of Southeast Asian Nations (ASEAN) in Asia; and the Veterinary Committee of the European Union (EU) and EUFMD in Europe. Not only will this ease the burden for all, but it will also, perhaps more important, result in harmonized plans and strategies for preventing and responding to emergency animal diseases within a region. This is particularly important in the case of transboundary animal diseases that, by definition, are prone to spread rapidly across national borders.
Potential avenues for collaboration include:
joint risk assessments leading to harmonization of import quarantine policies and other disease prevention strategies in a region;
joint development by countries that share common land borders of strategies and programmes to lessen the risk of FMD and other epidemic diseases being spread by the movement of potentially infected animals across the borders - through coordination of disease surveillance, quarantine, vaccination and other methods;
coordinated animal health programmes for shared ethnic groups who practise nomadism and transhumance across borders;
development of compatible disease reporting and information systems;
information exchange on disease occurrences, etc. at a national level, and at a local level near shared borders;
dividing responsibilities and possibly resources for preparing contingency plans for FMD and other shared high-threat diseases or at least exchanging ideas and draft plans;
reciprocal arrangements for development of laboratory diagnostic capabilities;
establishment of international vaccine banks;
joint training field exercises, workshops and other training programmes.
There are also compelling reasons why countries should cooperate in their control and eradication campaigns for shared epidemic livestock diseases. A regional approach with well-coordinated campaigns in all countries is far more likely to succeed and will reduce the subsequent risk for all countries to a greater extent than if countries proceed alone. The future export opportunities of the countries will also be enhanced if diseases are eradicated on a regional basis.