[AIDS and HIV infection among homosexual and bisexual men in Belém, Pará, Brazil, 1988-1990].

During three years (1988-1990) blood samples from 307 people were taken to test antibodies for Human Immunodeficiency Virus type 1 (HIV-1) in homo and bisexual males living in Belém, being 149 (48.5%) of the former and 158 (51.5%) of the later. All patients requested examinations spontaneously to find out their status. The ages of tested people ranged from 16 to 64 years old. Serologic diagnosis was made using an enzyme immunoassay (Abbott, São Paulo-Brasil) for screening and an indirect immunofluorescence test (FIOCRUZ, Rio de Janeiro-Brasil) for confirmation. If results were conflicting with these tests, western blot (Du Pont CO. Wilmington-USA) was performed to obtain a definitive result. Sixty-eight (22.1%) of all sera were positive. Although, the positivity in the homosexual group (26.2%) was more higher than in the bisexual group (18.3%). The positivity rate in both groups was directly proportional with the increase of age. Of course, people with less than 20 years old had only 3% of positivity, while between 20-29 had 18.1%, 30-39 had 34.5%, 40-49 had 40% and 50-59 had 50%. The projected curve of positivity, is progressive, that is to say, the risk of homo/bisexual males increases with age and is probably related to increased sexual activity. We conclude that more than one quarter of homosexual men are infected with HIV-1 in Belém.