Comparison of testing saliva and serum for detection of antibody to human immunodeficiency virus in Jamaica, West Indies

Background: In Jamaica the reported incidence of AIDS increased from 0.1/100 000 in 1985 to 20.2/100 000 in 1995. Here there is great reluctance to have voluntary blood testing and, indeed, any blood testing. Since only enzyme-linked immunoassay (ETA) was available for screening serum HIV-1 and 2 antibody, it was considered that a non-invasive saliva screening EIA could be an advantageous alternative. Objective: this study was designed to evaluate the OraScreen(TM) HIV Rapid Test, a new, simple saliva screening ETA for anti-HIV-1&2 and to compare its sensitivity and specificity with a standard serum anti-HIV screening EIA in current use in Jamaica. Study design: specificity and sensitivity of HIV antibody assays were compared in matched serum and saliva samples obtained from 257 volunteers from a family planning clinic and from visa applicants, representing a low risk population (Group I), and from 52 volunteers known to be HIV infected (Group II). Results: in Group I, 357 volunteers of unknown HIV status, one was positive for anti-HIV-1 in both serum and saliva. One other was seropositive but negative on saliva testing; confirmatory Western Blot (WB) testing on this serum was negative and this subject was tabulated as blood HIV negative. Fifty-one of the known seropositive volunteers (Group II) were saliva antibody positive. One saliva sample was inadequate and this individual was excluded from the study. Serum samples from three others in Group were grossly haemolysed but whose saliva samples were antibody positive. Conclusion: With the exclusion of one subject whose saliva sample was inadequate, the OraScreen(TM) HIV Rapid Test showed 100% specificity identifying 256/256 HIV antibody negative individuals, and 100% sensitivity by identifying 52/52 infected individuals as HIV antibody positive. (C) 2000 Elsevier Science B.V. All rights reserved.