ALTERNATIVE STRATEGY FOR DIAGNOSIS OF HIV -INFECTION IN SUBSAHARIAN AFRICA - INTEREST OF THE SEQUENTIAL COMBINATION OF 2 2ND-GENERATION ELISA AND RAPID TEST

The << conventional >> algorithm for HIV testing based on the confirma tion of all positive anti-HIV screening reactions by Western blot requ ires sufficient laboratory facilities and is expensive, that limits it s use in developing countries, such as in subsaharian Africa. The appa rition of second and third generation screening ELISA which are very s ensitive and specific, as well as the development of rapid tests which are simple, visually read, and sufficiently sensitive and specific, h as permitted the design of << alternative >> strategy for HIV testing utilizing the association of 2 ELISA and/or rapid tests, in order to l imit the use of a confirmatory assay. Alternative strategies are less expensive, yield generally very high sensitivity and specificity, and have proved to be valuable for African countries. In this study, 5 alt ernative strategies, using different associations of two second genera tion screening tests, one classical ELISA (Genelavia mixt(R)) and one rapid test (Test Pack HIV-1/HIV-2 AB(R)) have been retrospectively eva luated in the field in Bangui, Central African Republic, with a panel of 130 sera (prevalence of HIV infection: 42,7%). The strategy using t wo sequential screening tests (Test Pack HIV-1/HIV-2 AB(R) following b y Genelavia mixt(R)) with the confirmation of discordant results by We stern blot permitted to diagnose HIV-1 infection in Bangui with a sens itivity, a specificity and a positive predictive value of 100%, and to reduce the cost of more than 50% in comparison with the conventional strategy. Such an alternative strategy could be useful for the individ ual notification of HIV serology in Bangui.