How Do Rapid HIV Tests Compare with Standard HIV Screening Tests, Enzyme Immunoassays (EIAs)?
Clinical studies have demonstrated that the sensitivity2 and the specificity3 of rapid HIV tests are comparable to those of EIAs often used for screening. The negative predictive value4 of a screening test is high at the HIV prevalence observed in most U.S. testing settings (CDC, 1998). Therefore, a client with a negative rapid HIV test result can be told he or she is not infected. However, because HIV antibodies take time to develop, retesting should be recommended to persons with a recent possible exposure (sexual contact or needle sharing within 3 months). As with any screening test, the positive predictive value of a reactive rapid HIV test may be low in populations with low prevalence (see Appendix). Because some reactive test results may be false-positive, every reactive rapid test must be confirmed by a supplemental test (either Western blot or immunofluorescence assay [IFA]). (CDC, 1989). HIV Counseling with Rapid HIV Tests CDC’s revised Recommendations for HIV Testing of Adult
