Early warning enables rapid detection of the introduction or sudden increase in the incidence of a serious disease such as ASF before it develops to epidemic proportions and causes serious socio-economic consequences. It is based on disease surveillance, reporting and epidemiological analysis, leading to improved awareness and knowledge of the distribution and behaviour of disease outbreaks and infection. It enables forecasting of the source and evolution of the disease outbreaks and monitoring of the effectiveness of disease-control campaigns.
The success of a country's capability for rapid detection of introduction or increased incidence of ASF depends on the following:
It is beyond the scope of this manual to discuss these issues in detail. For more information, reference should be made to the FAO Manual on the preparation of national animal disease emergency preparedness plans (FAO Animal health manual No. 6) and the FAO Manual on livestock disease surveillance and information systems (FAO Animal health manual No. 8).
It is likely in many countries that few veterinarians or other animal health workers in the public or private sectors will have had any firsthand experience with ASF or other TADs. These diseases may never have occurred in the country or may have been exotic for a considerable period. If ASF is rated as a high-threat disease, this deficiency needs to be rectified by a training programme for all personnel who may be the first to come into contact with an incursion or outbreak of this disease. Because a disease may strike in any part of the country and because of staff turnovers, training programmes should be comprehensive and regular. This training must extend to staff in the remotest parts of the country as well as to agricultural extension officers, local authorities and pig owners.
It will obviously be neither practicable nor necessary to train personnel to a high level of expertise in these diseases. It is sufficient in most cases that trainees be at least familiarized with basic clinical, pathological and epidemiological features of ASF and what they need to do if they suspect one of these diseases. Perhaps the most important thing is to inculcate the understanding that if confronted by an unusual disease outbreak in pigs, in the field or in the diagnostic laboratory, staff should include ASF among the differential diagnostic possibilities and act accordingly. They should be trained in the steps to be taken to secure a confirmatory diagnosis, including collection and transport of diagnostic specimens and in the immediate disease-control actions to be implemented at a disease-outbreak site. More specialized training will be needed for personnel nominated to specialist diagnostic teams.
There are various training possibilities, including:
These programmes are critical but sometimes neglected aspects of preparedness planning for emergency diseases. They foster ownership and support for emergency disease control/eradication campaigns by livestock farmers and other stakeholders, engendering a bottom-up approach to planning and implementation of disease-control programmes that complements the top-down approach usually adopted by governments.
Communication strategies should aim to make stakeholders aware of the nature and potential consequences of ASF and other important livestock diseases and the benefits of prevention and eradication. They should always have an element of rallying the community to the common cause of preventing or fighting a disease epidemic, ideally resulting in the formation of sanitary defence groups and other farmer organizations.
One of the important messages to get across is that it is essential to notify and seek help from government animal health officials as soon as an unusual disease outbreak is seen in pigs. Information about how to do so should be available. Publicity campaigns should be directed towards farmers, local authorities and livestock traders.
It is recommended that a specialist ASF diagnostic team be nominated that can be mobilized when a suspect outbreak in pigs is reported in the field. These arrangements should be made well in advance of any emergency and the personnel should be available and equipped to travel to a disease outbreak site at short notice. Equipment should include everything needed for preliminary investigation of a disease and for collection and transportation of diagnostic specimens.
The composition of the diagnostic team will vary according to circumstances but may include:
The team would travel to a disease-outbreak site with local veterinary staff as directed by the CVO and would:
The team should have the authority to take any immediate disease-control actions at the outbreak site. It should report its assessment immediately to the state, provincial or regional veterinary officer and the CVO, specifying steps taken to secure a confirmatory diagnosis and giving advice on further disease-control strategies, including declaration of infected and surveillance zones.
Rapid and certain diagnosis of diseases can only be assured in fully equipped laboratories with a range of standard diagnostic reagents, experienced staff and a sufficient throughput of diagnostic specimens to maintain expertise. Development of diagnostic expertise for exotic disease tests requiring handling of the live agent should only be attempted in microbiologically secure laboratories.
It is consequently impractical and excessively costly for most countries to maintain a national veterinary diagnostic laboratory with full capability for confirmatory diagnosis of all transboundary and other emergency diseases, many of which will be exotic. It is to be expected, however, that countries with significant livestock populations should have a veterinary diagnostic laboratory equipped and competent to undertake standard techniques in pathology, virology, bacteriology and serology to the level where preliminary identification of aetiological agents for emergency livestock diseases could be attempted. If ASF is deemed to be a high-threat disease, consideration should be given to developing capabilities for some primary key diagnostic tests, such as fluorescent antibody tests.
Containers for transporting specimens should be kept at central, state or provincial veterinary laboratories and should be made available for field veterinary officers and specialist diagnostic teams. The containers should ideally consist of leakproof primary vessels such as glass universal bottles with a metal screw cap and rubber washer or good-quality plastic screwtop jars. They are packed into leakproof secondary containers such as steel paint tins or styrofoam cold boxes with absorbent material and an icepack. This is not necessary if chilling is not an initial option and the samples have been collected into formalin or glycero-saline. The containers are finally placed in robust outer containers with clear labels. Specimen advice notes should also be provided.
There is a worldwide network of OIE reference laboratories and collaborating centres for ASF, which provide advice and assistance. Their names, contact details, subjects and geographical areas of responsibility are given in Annex 1.
As part of their ASF contingency planning, countries should establish contact with appropriate reference laboratories and collaborating centres and determine the nature and range of diagnostic specimens or isolated agents that should be sent for confirmatory diagnosis or further characterization. It is important to obtain information about transport media that may have to be added, methods of packaging, refrigeration, labelling and any necessary customs or IATA declarations. This information should be documented in plans.
It is very important that potential or confirmed aetiological agents from emergency disease outbreaks be sent to the appropriate international reference laboratory for further characterization. It is recommended that several isolates from different geographical locations and different phases of the outbreak be forwarded. Submission of samples to any laboratory outside the country of origin should always be subject to prior agreement with the recipient. Samples must be transported in containers meeting IATA standards.
Full use of reference laboratories and collaborating centres should be made for help with such things as training opportunities, provision of specialized advice in planning and standardized diagnostic reagents.
