The Virology section is a diagnostic laboratory concerned with the processing of a variety of samples to test the presence of antibodies to a number of viral diseases. Samples mostly received include sera, organs, and tissues. Apart from the actual testing done in the laboratory, some samples received are sent to regional and international laboratories, for tests not performed locally. The laboratory comprises of three units serology, virus isolation and tissue culture.

 1. Serology unit

This unit is mainly concerned with Foot and Mouth Disease (FMD) testing. Sera from animals such as cattle, goats, sheep and wild ungulates are tested for the presence of antibodies to the FMD virus. Testing for FMD is done in specimens collected from both vaccinated and non vaccinated animals. Imported animals are tested to ensure absence to the disease and antibody to the FMD viruese. This is important since these animals mostly go into the FMD free and export areas of Botswana which are supposed to be free from the disease. However, with vaccinated animals within the other zones of Botswana, this is done to monitor the antibody level elicited by the vaccine and this is done to attain information that could assist in declaration of FMD free status in areas where vaccination was carried out.

The BNVL collaborates with the Botswana Vaccine Institute (BVI) in this area.  Antibodies to Chlamydia disease are also tested in serology whereas samples for African horse sickness, Bovine ephemeral fever, and bovine leucosis, to name a few are sent to outside laboratories for testing.

 2. Virus isolation unit

     Birds

The virus isolation unit as the name suggest deals with the isolation of avian viruses particularly, Newcastle Disease, Avian Influenza and Fowl pox viruses from fowls such as chickens, farmed ostriches and wild birds. Samples used for virus isolation are organs (liver, lung, kidney, trachea, and spleen) collected  from carcasses from suspected cases. Avian serology (detection of antibodies in serum samples of fowls) is also done in this unit parallel to virus isolation (particularly, antibodies to Newcastle disease virus and to avian influenza virus in poultry and ostrich serum samples). The diagnosis of infectious bursal disease (Gumboro disease ) is done in this unit by detection of either antibodies to the virus or detection of the viral antigen.

    Mammals

Isolation of mammalian viruses is at present restricted to rabies. FMD virus isolation from tissues or probang samples is conducted by the BVI.

Future prospects

With the advancement in the tissue culture technology  it will be possible to include isolation of other viruses like African horse sickness virus, bovine viral diarrhoea, infectious bovine rhinotracheitis, canine distemper which are currently tested for outside the country.

Support in animal and public health programs

Most of the samples received in this unit are mainly for Newcastle disease testing and avian influenza due to both public health and economic importance in the animal farming community. This is also carried out to monitor the presence of antibodies in ostriches before live birds or products are exported. Monitoring of these diseases facilitates trade between countries.

3. Tissue culture

The unit’s  primary goal is for supporting the isolation and identification of mammalian viruses through propagation and maintenance of cell cultures. Permanent cell lines (e.g. MDBK cells, BHK21, RK13 etc) will be procured from reputable institutions and maintained in the laboratory.

Costs involved in virus analyses