AIDS incubation in 1891 HIV seroconverters from different exposure groups

This study compares AIDS incubation in different geographic areas, calendar time of infection, exposure group and age at exposure. Investigators from North America, Europe and Australia contributed data from 1891 people for whom dates of HIV seroconversion were known. We excluded subjects not enrolled in prospective studies at entry and those with more than 25 months between last negative and first positive sera; we also censored subjects at the time last seen and excluded all follow-up after 1987 in order to minimize the impact of newly developed prophylactic therapies. The final analysis cohort contained 1171 subjects. Using actuarial methods, no differences in incubation times were found among homosexual men infected in different continents or in different years (prior to and after 1 January 1985). Among hemophilic people, children developed AIDS more slowly than adults (P = 0.02), and hemophilic adults developed AIDS more slowly than homosexual men (P less than 0.05), mainly because homosexual men had an added risk of Kaposi's sarcoma. Progression time to AIDS was significantly faster in older hemophilic men, but not in older homosexual men. These data illustrate that AIDS incubation may differ in different exposure groups, probably because of different exposures to potential opportunistic pathogens.