The action plan is a set of instructions covering controls to be implemented during an ASF emergency, from first suspicion of the disease to final eradication. It details actions to be taken from the first report of suspected ASF.
Since the veterinary structure differs from country to country, this chapter provides a general guide to actions to be carried out during each phase of an outbreak of ASF. Each country should develop its own action plan, in which persons responsible for each action should be identified. Lines of communication between pig owners, field and national veterinary services must be identified and made known to all parties. These communication lines underpin the chain of command that will be activated in the event of suspicion of ASF. The success of the action plan depends on each link in the chain of command functioning as specified in the plan.
It is expected that countries will prepare detailed generic operating procedures applying to ASF and other epidemic diseases. Additional manuals may be required to cover the zoosanitary code of practice in high-risk enterprises such as meat-processing plants and livestock markets.
Countries may wish to consult the AUSVETPLAN manuals on control-centre management, decontamination, destruction of animals, disposal procedures, public relations, valuation and compensation, laboratory preparedness, artificial insemination centres, dairy processing, meat processing, feedlots, saleyards and transport. The standards that can be attained will vary from country to country, however, and it is advisable for countries or regions to develop their own enterprise manuals based on local conditions unless considerable similarity exists between their situation and that of Australia, an island with a highly developed economy and commercial agricultural sector and a sparse and sophisticated human population.
The investigation phase exists when a report of probable ASF is received by the veterinary services. It should be a clearly understood legal obligation of any citizen suspecting the presence of ASF or other serious animal disease to report to a member of the veterinary or animal health services either directly or through the chain of communication, for example the village assembly person, agricultural-extension officer or district authority. A suspicious index case or exceptionally high mortality among pigs are most likely to be reported to the local veterinary authorities by an animal-health or agricultural-extension officer, an abattoir or meat-hygiene officer, farmers and livestock owners, community leaders, or private veterinary practitioners and ancillary veterinary staff such as community-based animal health workers employed by government or non-governmental organizations.
Once a report of suspected ASF is received, the following actions must be taken:
On receiving information that could indicate ASF, the local veterinary authority should carry out an investigation by visiting the location of the index case/s to gather information about clinical and epidemiological features of the case and collect specimens to aid diagnosis. Specimens should be transported on ice, or in 50 percent glycerosaline if refrigeration is not available, to the nearest laboratory as soon as possible. The remaining pigs should be examined. If there are grounds to suspect ASF, such immediate quarantine and movement restrictions as are within the power of the local authority should be imposed. In the absence of legal powers, every effort must be made to obtain community cooperation to prevent movement of pigs and pig products, pending further investigation.
Depending on the size of the country and veterinary hierarchy, lines of communication from farm level to national veterinary authority may contain few or many links. In essence, faced with the possibility of ASF, the report should reach the DVS as soon as possible. Investigating false alarms may result in inconvenience and unnecessary expenditure but the consequences of missing the index case because somebody with imperfect knowledge of the disease was not sufficiently convinced can result in catastrophe. In countries previously uninfected, it is most unlikely that the index case will be the first to have occurred.
If the investigation shows that the circumstances are not suggestive of ASF or an alternative diagnosis can be made, a false alarm may be declared and operations wound down. Declaration of a false alarm should always be accompanied by an expression of public gratitude to those who reported the index case, to encourage people to report suspicion of ASF without fear of being proved wrong. To control important diseases of livestock, it is most important to develop a culture of reporting suspicious events.
If clinical and epidemiological results are highly indicative of ASF, particularly the death of large numbers of pigs of all ages over a short period of time, the main actions required are:
The DVS or CVO should:
Directors of veterinary services in neighbouring countries should be alerted, because of the potential for rapid transboundary spread before diagnosis has been confirmed, especially in continental countries with porous borders.
If national and local pig farmers' associations exist, alerting them to the situation as soon as possible will assist in ensuring their support and cooperation should ASF be confirmed and will have a beneficial effect on enforcement of quarantine.
The ASF expert team, in collaboration with local veterinary personnel, should investigate the case in situ by:
After a visit to potentially infected premises, the team leader should ensure that proper disinfection procedures are carried out to prevent iatrogenic transmission of the disease.
Specimens should be delivered with minimum delay, chilled or preserved, to a laboratory with the capacity to carry out the diagnosis. In the case of countries without laboratory diagnostic capacity for ASF, they should be sent to a reference laboratory.
If the investigation in situ indicates other foci of infection as either the source or recipient of infected material, these foci should be investigated immediately, provided that the diagnostic samples from the index case have been delivered. The same procedure should be followed as for the index case.
The operational phase is initiated when ASF occurrence has been confirmed and an ASF emergency is declared. Immediate actions required are:
The declaration of infection should be sent by the DVS to global authorities such as OIE and FAO and regional organizations and officially communicated to neighbouring countries.
Delay in reporting to neighbouring countries can have serious consequences in terms of ASF control and political relations.
The minister responsible for the veterinary department should be made aware the importance of at least the List A diseases before any outbreak occurs. Immediately upon confirmation of ASF, an interview should be arranged to brief the minister about the current situation, the salient facts about the disease, legislation affecting disease control and the budget for disease-control measures. This should be accompanied by a realistic estimate of the cost to the country should control fail, which should be prepared in advance and regularly updated to accommodate inflation and changing circumstances such as growth and modernization of the pig industry. Permission to mobilize the emergency fund for ASF control should be obtained.
An effective organized public-awareness campaign is probably the most important aid in control of ASF. The campaign must be an intrinsic part of the action plan. Countries will have characteristics that determine the type of campaign that will succeed best but certain basic rules apply to all countries.
FIGURE 12
Public-awareness campaign
An effectively organized public-awareness campaign is required at each phase to ensure public
cooperation.
If there are national and local pig farmers' associations, it is politic to ensure that they are informed of the situation ahead of the general public. Their cooperation is central to the success of control measures and like neighbouring countries they will be alienated by receiving the news at second hand.
Destruction of infected and in-contact pigs should be carried out by a team equipped to destroy pigs in a humane manner acceptable to owners, dispose of carcasses in such a way as to prevent retrieval and consumption of meat and decontaminate premises and themselves. Disposal of carcasses and infected material such as bedding and residual feed by deep burial and incineration is recommended. This should take place as close as possible to the infected premises, as transport of potentially infected carcasses to distant sites is not recommended: dangers include spillage of infected fluids, breakdown of vehicles and theft. Informed pig farmers do not want vehicles carrying potentially infected material in the vicinity of their properties. Removal of carcasses to distant burial sites contravenes the ban on movement of pigs within and from infected areas and sets a bad public example. Depopulation of pig farms should be immediately followed by cleaning and disinfection, with destruction of all material such as faeces, bedding and residual feed and cleaning and disinfection of water and feed troughs. Disinfection may be carried out with 2 percent sodium hypochlorite or a detergent-based virucidal agent. Teams should wear protective clothing and disinfect themselves, particularly their hands and boots, after operations.
Before destruction is attempted, owners must be assured of compensation at market-related prices. These prices must be determined by the price per kg that the pig would realize if sold normally. If possible, pigs should be weighed in the presence of owners to demonstrate the fairness of the price offered. Prices for different classes of pigs may be established but this gives rise to problems in countries where improved and local unimproved pig breeds are used, as the latter are much smaller and have a correspondingly lower market value. While overpayment resulting from classifiying 30 kg village pigs as 60 kg finishers will have a positive effect on owner cooperation, it will not be realistic in terms of the amount of money available for compensation.
This is the most difficult aspect of control. It is based upon:
Any national action plan should include innovative measures to support movement control, including participation of representatives of the pig industry in road blocks, dissemination of pamphlets and posters illustrating the consequences of illegal movement and incentives for reporting illegal movement that will outweigh the advantages of ignoring it.
This should be carried out by local animal health officers and agricultural extension officers, who should enlist the support of pig producers and village authorities and identify clear lines of reporting and communication. This is facilitated by holding public-information days in infected foci and areas most likely to become infected. Records of pig farming that constitute the inventory of the national herd should be updated. All pig producers, especially in the areas surrounding infected foci, should be visited at least twice, with a two-week interval, to ensure that no untoward deaths have occurred. Veterinary officials versed in the clinical signs of ASF should carry out inspections at all livestock markets and abattoirs and question the sellers. They should have powers to detain pigs showing suspicious signs of disease or originating from farms that have experienced increased mortality or are situated in or close to infected areas. Blood and organs from slaughtered pigs may be submitted to the national diagnostic laboratory. Regular reporting and dissemination of information, for example by a weekly or bi-weekly epidemiological report, should be encouraged.
FIGURE 13
Sentinel animals
Sentinel animals need to be left to roam around previously infected premises to ensure that the
disease agent is no longer present.
Surveillance may be reinforced by local, regional and national workshops on recognition and management of ASF. These should be held at regular intervals to ensure that new entrants are informed and trained. It is however, realistic to accept that considerable refreshment of past training will be required, especially in the absence of a disease over a long period.
When ASF is not confirmed, the DVS should inform all parties that the emergency situation has ceased to exist. If ASF had been confirmed, the stand-down phase begins when the DVS is satisfied that all operations for containment, control and elimination of infected foci have achieved their goal. How soon this will occur after the initial outbreak will depend on circumstances, including whether other foci were discovered, their extent and the success of the stamping-out measures. In practice, if no further outbreaks have occurred for a two-month period after the initial outbreak, normal trade in pigs and pig products can be resumed, although this should be subject to veterinary surveillance for at least the first month or two. Sentinel pigs may be introduced into formerly infected premises 40 days after depopulation and disinfection. Failure of these pigs to develop signs of disease within two or three weeks of introduction will help to confirm that the outbreak has been controlled.
