The Vancouver Lymphadenopathy-AIDS Study: 2. Seroepidemiology of HTLV-III antibody

Testing for antibody to human T-lymphotropic retrovirus (HTLV-III) was carried out in 448 participants in the Vancouver Lymphadenopathy-AIDS (acquired immune deficiency syndrome) Study. The overall prevalence rate of seropositivity was 34%. Of 130 seronegative subjects followed for an average of 8.5 months, 14 became seropositive; thus, the approximate annual seroconversion rate was 15%. More than 100 male sexual partners in one's lifetime, frequent receptive anal intercourse, fisting, a history of gonorrhea or hepatitis, and frequent sexual contact in clubs were found to be independent risk factors for HTLV-III seropositivity.