Acquired Immunodeficiency Syndrome in Low-Incidence Areas

Abstract

Serum specimens from the cohort of persons who attended sexually transmitted disease clinics in New Mexico during a two-month period were tested for human immunodeficiency virus (HIV) antibody. Twenty-seven (2.0%) of 1374 serum specimens had repeatedly low-positive reactions by enzyme-linked immunosorbent assay testing, and 22 (1.6%) had repeatedly high-positive reactions. All sera (sufficient for testing by Western blot) with low-positive reactions gave negative results, and all sera (sufficient for testing by Western blot) with high-positive reactions gave positive results. All persons whose serum had high-positive reactions were male. Most (86%) had been seen at the only urban sexually transmitted disease clinic in New Mexico, and most (72%) were openly gay or bisexual. Of all gay and bisexual men evaluated, 14% (16/112) had high-positive reactions. Rapid plasma reagin positivity was significantly associated with HIV enzyme-linked immunosorbent assay low (false) positivity. The relatively high rate of HIV seropositivity among gay men with other sexually transmitted diseases indicates that transmission of acquired immunodeficiency syndrome is continuing in this low-incidence area and documents the need for testing and counseling programs in sexually transmitted disease clinics.

Laboratory methods for early detection of human immunodeficiency virus type 1 in newborns and infants.

“…Specimens that are repeatedly reactive on the EIA should be confirmed by the HIV-1 Western blot (immunoblot) assay. False-positive results on the EIA have been shown to occur in patients with a positive rapid plasma reagin test (37), hemophiliac patients (92), and patients on hemodialysis (77). Kuhnl et al have also detected cross-reacting antibodies to HLA DR4 antigen (found in H9 cell lines) which seroreact when tested by EIA (56).…”

Practical diagnostic testing for human immunodeficiency virus

“…These false-positive results can be due to intrinsic variability in test performance, heat inactivation of serum, HLA antibodies with specificity for HLA DQ3 and DR4 antigens (found in the H-9 cell line used to grow stock virus), and probably other contaminating antigens from cell lines (12,71). False-positive EIA results have been reported to be as high as 19% in hemophilia patients (113), 13% in alcoholic patients with hepatitis (83), 4% in hemodialysis patients (96), and 24% in patients who have a positive rapid plasma reagin test (41). Therefore, confirmatory testing of all EIA repeatedly reactive specimens is essential.…”