Serologic validation of HIV infection in a tropical area

The authors have defined human immunodeficiency virus type 1 (HIV-1) serologic reactivity in Brazilians living in an area endemic for tropical diseases. Enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) analyses were performed on 342 patients with diseases including Chagas diseases schistosomiasis typhoid fever helminthiasis and cutaneous and visceral leishmaniasis. 9% of the visceral leishmaniasis patients sera reacted in the HIV-1 ELISA but all were WB negative. A total of 224 HIV-21 ELISA repeatedly positive sera also were HIV-2 WB tested. They were drawn from a population of 19230 individuals including AIDS patients blood donors homosexual men intravenous drug users pregnant women individuals with hemophilia and tuberculosis and sexually transmitted diseases patients. The WB results were analyzed using 5 different interpretative criteria for WB positivity. The Centers for Disease Control (CDC) and the WHO criteria were the most sensitive and specific for identifying HIV-1 infected- individuals. The Wb pattern was similar to that seen in the US. Envelope (ENV) protein antibodies were highly predictive of HIV-1 infection; none of the AIDS patients lacked ENV protein reactivity. THe authors conclude that tropical diseases studied only visceral leishmaniasis is associated with false-positive HIV-2 ELISA tests. Current CDC and WHO criteria for interpretation of HIV-1 W tests are appropriate for Brazil. (authors)