Serological diagnosis of human immuno-deficiency virus in Burkina Faso: reliable, practical strategies using less expensive commercial test kits.

Reported are the results of a cross-sectional survey in Burkina Faso to identify reliable, practical strategies for the serological diagnosis of HIV-1 and/or HIV-2 infections, using less-expensive commercial test kits in various combinations, as an alternative to the conventional Western blot (WB) test, which costs US$ 60. Serum samples, collected from blood donors, patients with acquired immunodeficiency syndrome (AIDS) and pregnant women, were tested between December 1995 and January 1997. Twelve commercial test kits were available: five Mixt enzyme-linked immunosorbent assays (ELISA), three Mixt rapid tests, and four additional tests including monospecific HIV-1 and HIV-2 ELISA. The reference strategy utilized a combination of one ELISA or one rapid test with WB, and was conducted following WHO criteria. A total of 768 serum samples were tested; 35 were indeterminate and excluded from the analysis. Seroprevalence of HIV in the remaining 733 sera was found to be 37.5% (95% confidence interval: 34.0-41.1). All the ELISA tests showed 100% sensitivity, but their specificities ranged from 81.4% to 100%. GLA (Genelavia Mixt) had the highest positive delta value, while ICE HIV-1.0.2 (ICE) produced the most distinct negative results. Among the rapid tests, COM (CombAIDS-RS) achieved 100% sensitivity and SPO (HIV Spot) 100% specificity. Various combinations of commercial tests, according to recommended WHO strategies I, II, III, gave excellent results when ICE was included in the sequence. The best combination of tests for strategy II, which achieved 100% sensitivity and specificity, was to use ICE and COM, the cost of which was US$ 2.10, compared with US$ 55.60 for the corresponding conventional strategy. For strategy III, the best combination, which achieved 100% sensitivity and specificity, was to use ICE, ZYG (Enzygnost Anti HIV-1/HIV-2 Plus) and COM, the cost of which was US$ 2.90 (19.2 times lower than the corresponding strategy requiring WB). No rapid test combination showed 100% sensitivity and specificity. Our results indicate that the serodiagnosis of HIV in Burkina Faso is possible by using reliable, less-expensive strategies which do not require Western blot testing. Moreover, there is a choice of strategies for laboratories working with or without an ELISA chain.