Laboratory diagnostic capabilities

Several computerized animal health information systems are available. One possible system is the transboundary animal disease information system (TADinfo). This has been developed by FAO and is particularly useful for handling disease emergency situations. It is also used for routine/endemic diseases. The programme can be obtained from FAO2, and FAO can provide assistance in installing it.

laboratory dIagnostIc caPabIlItIes

The rapid and definitive diagnosis of diseases can only be assured in properly equipped laboratories. Such a laboratory will have a capacity to conduct a range of standardized diagnostic assays, with trained, experienced staff and a sufficient throughput of diagnostic specimens to maintain proficiency. There are many different types of assays, but on many occasions, definitive diagnosis will depend on detecting the presence of the organism (i.e. tests that detect part or all of the organism rather than antibodies). Assaying antibodies is also important, often simpler to carry out, and is important in the ‘proof-of-freedom’ phase.

Development of diagnostic expertise for TADs for assays which require handling the live agent should only be attempted in microbiologically highly-secure (biosafe) laboratories. This is particularly true where the organism has zoonotic potential. Biosafety (biocontainment) is important.

The tests to be used should be internationally validated and must be safe for the operators and sustainable. It may not always be possible to have fully confirmatory tests for all the pathogens responsible for the priority diseases. Recent developments, such as polymerase chain reaction (PCR)-based assays, offer the possibility of rapid, sensitive and specific tests for pathogens, but maintaining such a facility is not always easy. Reagents are expensive and go out of date, and maintaining a sufficiently trained staff requires frequent refresher or training courses.

It would therefore be impractical and excessively costly for most countries to maintain a national veterinary diagnostic laboratory that has full capabilities for confirmatory diagnosis of all transboundary and other emergency diseases, many of which will be exotic. For very high-threat TADs, consideration should be given to developing capabilities for some key diagnostic tests (e.g. antigen and antibody detection tests).

The OIE Manual of Standards for Diagnostic Tests and Vaccines provides authoritative information on diagnostic procedures for a range of important diseases.

Laboratories should make specimen transport containers readily available for field veterinary officers and specialist diagnostic teams. These should ideally consist of leak-proof primary containers, such as polystyrene or polyurethane universal bottles with a screw-cap. These are then packed into a leak-proof secondary container (e.g. a wide-opening canister) with absorbent material and an ice pack (where chilling is required). This is finally placed into a robust outer container with good labels. Specimen advice notes should also be provided.

It should also be normal practice to send samples to regional and world reference laboratories for confirmation of test results and also to ensure that a complete database of pathogens and regional and worldwide patterns of occurrence can go on record. IATA transport regulations are a specialist area and require conforming to different international

2 http://www.fao.org/ag/AGAinfo/programmes/en/empres/tadinfo/default.html