Field evaluation of rapid HIV serologic tests for screening and confirming HIV-1 infection in Honduras.

Objective: To determine the ability of simple, rapid tests to identify HIV-1 antibody-positive specimens in field settings using the World Health Organization's (WHO) alternative testing strategies.

Design: Three-phase evaluation of simple, rapid assays using banked specimens and prospectively collected serum specimens at regional hospitals and rural clinics.

Methods: Seven test (Retrocell, Genie, HIVCHEK, SUDS HIV-1, Testpack, Serodia HIV-1, and HIV-1/2 RTD) were evaluated and results compared with standard enzyme immunoassay (EIA) and Western blot results (phase 1). Further evaluation consisted of prospective testing of routine specimens at regional (phase 2; n = 900) and rural, peripheral laboratories (phase 3; n = 1266) throughout Honduras with selected assays.

Results: Sensitivity and specificity were calculated for each assay and combination of assays for each phase to evaluate the effectiveness of the WHO alternative testing strategies. All tests in all phases were > 99% sensitive after correcting for technical errors, with two exceptions (SUDS, phase 1; HIVCHEK, phase 3). In phase 3, where the testing algorithm was diagnostic, several combinations of assays were 100% sensitive and specific using WHO strategy II or III. For the Honduras Ministry of Health, the combination of Retrocell and Genie was found to be equally sensitive, more specific (no indeterminate results), and less expensive than EIA/Western blot.

Conclusion: Combinations of rapid, simple HIV antibody assays provide sensitivity and specificity performance comparable to EIA/Western blot. Application of these combinations in the WHO alternative testing strategies provides an inexpensive and effective method of determining HIV status. Assay combinations using these strategies can be easily performed in small, rural laboratories and have been implemented in routine HIV screening in Honduras.