( By WHO - OMS, 1999 )
Develop locally adapted working case definitions for VHFs and yellow fever, as well as guidelines to help health workers at all levels recognize suspicious trends and signal an epidemic alert.
The prompt diagnosis of a VHF outbreak’s cause requires a competent laboratory’s analysis of a representative sample of specimens. Epidemic preparedness should give this utmost priority, along with assessing the capacity of national laboratories; identifying reference laboratories; and ensuring methods of diagnostic specimen transport.
Most of the viruses causing VHF (excluding dengue haemorrhagic fever) are classified as “Biosafety Level 4” pathogens. This biohazard requires analysis at special facilities that provide maximum containment.
Attempts to isolate the virus should be undertaken only at approved high containment laboratories. Therefore, these should be identified in advance and contacts established with the nearest specialist laboratory to obtain details of necessary precautions for packing and transport of specimens.
Serology can be carried out in standard laboratories only if it is possible to inactivate specimens and reagents.
The measures listed below should also be taken:
- identify in advance qualified local team members skilled in assessing VHF outbreaks (e.g. an epidemiologist, clinician/entomologist, virologist, and veterinarian);
- put in place advance provisions for obtaining rapid outside specialist support if qualified personnel are not locally available;
- obtain advice from a virologist on the specimens needed, precautions required for collection, the necessary equipment, and shipment procedures (consider International Air Transport Association (IATA) shipping restrictions);
- identify channels and means for rapid communication between peripheral areas and subnational/central levels - satellite telephone and facsimile may be required; and
- identify a knowledgeable individual to communicate with the press and develop a strategy to deal effectively with their inquiries.