AEGiS-13IAC: HIV variants and rapid tests for HIV infection diagnosis.

13th International AIDS Conference

Durban, South Africa - July 9-July 14, 2000

HIV variants and rapid tests for HIV infection diagnosis.

Int Conf AIDS 2000 Jul 9-14; 13:(abstract no. MoOrA108)

Makuwa M, Souquiere S, Niangi MT, Rouqvet P, Apetrei C, Simon F;;; M. Makuwa, Centre International De Recherches Scientifiques, PO Box 769, Franceville, Gabon, Tel.: +241 677 092, Fax: +241 677 295, E-mail: makuwa@cirmf.sci.ga

BACKGROUND: Several diagnostic strategies using rapid tests were proposed during the last ten years and recommended for implementation in developing countries. Initial screening assays for HIV diagnosis have been evaluated using panels of sera from subtype B-infected patients. However, the discovery of HIV-1 group O prompted manufacturers to change tests design in order to cover a higher diversity. Recent described group N and new SIVs raised concerns regarding the accurate detection of divergent variants which might eventualy circulate and emerge. We evaluated different rapid tests on a panel of diverse human and primate samples in order to evaluate their performances and limitations for use in alternative strategy.

METHODS: Serums: Human panel: 173 samples: 50 group M (26A, 1B, 1C, 6D, 2F, 4H, 10 ind), 9 group O, 12 HIV-2, 2 HIV1 + 2, 6 with indetermined WB; 41 serial samples from 9 seroconverters and 56 sera from negative STD patients; Primate panel: 45 samples from 6 species, including 14 serial samples from 2 experimental seroconversions (SIVmac and SIVrcm), confirmed as either positive (n = 35) and negative (n = 10) by PCR. Tests: ELISA and WB (Genscreen 2 and Genelavia, Sanofi Diagnostic Pasteur); Rapid tests: Genie II and SFD HIV 1/2 PA (SDP), Immunocomb II BiSpot, DoubleCheck II and Recombigen HIV 1/2 (PBS Orgenics), Determine HIV 1/2 (Abbott).

RESULTS: Genscreen 2 was choosed gold standard. Genie II was rejected because of lack of detection of two human samples in the group M panel. Performances of remaining tests on human and simian samples (excepting seroconversion panels) are depicted in Table. Testing the seroconversion panel revealed dramatic lack of sensitivity in detecting HIV/SIV seroconversions, a delay > 2-8 days being observed in positivity of rapid tests when compared to Genscreen and WB reactivity. Sens Spec PPV NPV Efficiency Genelavia 100 100 100 100 100 Immunocomb 100 94.6 97.4 100 98.2 DoubleCheck 95.5 100 100 96.6 97 Recombigen 100 100 100 100 100 Determine 97.3 96.4 98.6 97.7 97 SFD 100 94.6 97.4 100 98.2

CONCLUSION: Although improvements of rapid tests performances recommend their use in alternative strategies of HIV diagnostic in developing countries, their lack of sensitivity during seroconversions represent a major limitation in their use in screening of the blood banks. These results urge the developement of appropriate tools and local evaluations prior to implementing alternative strategies. The use of rapid tests instead of more robust, sensitive and cheaper ELISAs reflects the inconsistency of public health strategies in controling the spread of HIVs.

Keywords: AEGIS, HIV Infections, HIV-2, HIV-1, HIV Seropositivity, Sensitivity and Specificity, SIV, AIDS Serodiagnosis, Mass Screening, Enzyme-Linked Immunosorbent Assay, Evaluation Studies, Developing Countries, Immunoenzyme Techniques, Human, diagnosis
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MoOrA108