title: A simplified and less expensive strategy for confirming anti HIV-1 screening results in a diagnostic laboratory in Lubumbashi, Zaire.
abstract: The conventional algorithm for HIV testing based on the confirmation of all positive anti-HIV screening reactions by Western blot (WB) is too expensive for developing countries. We investigated the validity of confirming positive screening assay reactions by a second screening test, limiting the use of the supplemental assay to the discrepant test results (algorithm 3), or screening all sera with 2 different assays and retesting all discrepant results by a supplemental assay (algorithm 4) on a panel of 519 sera in a regional reference laboratory in Lubumbashi, Zaire. Combining the Vironostika anti-HTLV-III ELISA with HIV Chek 1 + 2 or Clonatec Rapid HIV 1/2 Ab on all samples and retesting the discrepant results in WB or a line immunoassay (INNO-LIA) (algorithm 4), yielded a sensitivity of 100% and specificities of 98.4% and 99.0% respectively, at costs of 7.3 US $ and 9.3 US $ per test, respectively, for a 40% prevalence of HIV antibody positive samples. The conventional algorithm scored a sensitivity of 97.1% and a specificity of 100% for 11.3 US $ per test. The testing strategy of combining HIV Chek 1 + 2 and Clonatec Rapid HIV 1/2 Ab, an interesting option for small isolated centra, had a 96.6% sensitivity, but yielded only a slightly better specificity of 99.0%, as compared to 97.8% for HIV Chek alone. The price of combining the two simple assays using algorithm 3 was 6.8 US $ per test, using algorithm 4 was 10.6 US $. HIV testing strategies based on ELISA and a simple HIV test are a valuable alternative for reference laboratories faced with a high prevalence of HIV positive samples.
authors.affiliation: Centre Régional de la Lutte contre le SIDA, Lubumbashi, Zaïre.
authors.forename: G
authors.initials: G
authors.lastname: Laleman
authors.forename: M
authors.initials: M
authors.lastname: Kambale
authors.forename: I
authors.initials: I
authors.lastname: Van Kerckhoven
authors.forename: N
authors.initials: N
authors.lastname: Kapila
authors.forename: M
authors.initials: M
authors.lastname: Konde
authors.forename: U
authors.initials: U
authors.lastname: Selemani
authors.forename: P
authors.initials: P
authors.lastname: Piot
authors.forename: G
authors.initials: G
authors.lastname: van der Groen
mesh_terms: D015492:AIDS Serodiagnosis / Q000191:economics / Q000379:methods*; D000465:Algorithms; D015153:Blotting, Western / Q000191:economics; D003365:Costs and Cost Analysis; D015023:Democratic Republic of the Congo; D006801:Humans; D012680:Sensitivity and Specificity