HIV Testing

In Botswana, HIV infection is usually diagnosed by testing for antibodies against HIV. However, Polymerase Chain Reaction (PCR) using Dried Blood Spots (DBS) is becoming more widely used in the diagnosis of HIV infection in children below 18 months of age.

Methods of HIV testing

There are several methods used to diagnose HIV. Enzyme-Linked Immunosorbent Assay (ELISA), Rapid HIV test and Polymerase Chain Reaction (PCR) are the methods used in Botswana. ELISA and rapid HIV tests utilize the same principle of detecting antibodies produced by the human body as a reaction to HIV infection. However some people who tested with ELISA did not come back for their results and therefore did not receive timely treatment. Therefore Rapid HIV test was introduced in 2005. PCR, on the other hand, detects the virus’s genetic material such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA).

Window period

The “window period” is the period from initial infection with HIV to the time when the body has produced enough antibodies to be detected with an HIV antibody test.  This period is usually 3 months. The window period thus means that a person who has been recently infected with HIV may test negative for the HIV antibody because their body has not produced enough antibodies to be detected by the test.  Although tested negative, such a person can still pass the virus to others. A patient/client with a negative HIV test result and with recent high-risk exposure (unsafe sex, STI or STI exposure, pregnancy) should be cautioned about the window period and advised to return for a repeat HIV test in 3 months. Such patients/clients who may be in the window period should reduce their risk of transmitting the virus during this period and practice safer sex at all times.

In Botswana, all HIV test kits to be used in the country should be approved by Ministry of Health. The National health Laboratory evaluates and recommends kits based on their sensitivity and specificity. All HTC sites must use MOH approved test kits and HIV testing algorithms. Botswana currently uses parallel testing for both ELISA and rapid HIV tests.