Temporal trends in human immunodeficiency virus type 1 seroconversion 1984-1989. A report from the Multicenter AIDS Cohort Study (MACS)

• Published in: American journal of epidemiology Vol. 134; no. 4; p. 331
• Main Authors: Kingsley, L A, Zhou, S Y, Bacellar, H, Rinaldo, Jr, C R, Chmiel, J, Detels, R, Saah, A, VanRaden, M, Ho, M, Muñoz, A
• Format: Journal Article
• Language: English
• Published: United States 15.08.1991
• Subjects: Age Factors; Baltimore - epidemiology; Bisexuality; Chicago - epidemiology; Cohort Studies; Continental Population Groups; HIV Seropositivity - epidemiology; HIV Seroprevalence; HIV-1; Homosexuality; Humans; Incidence; Los Angeles - epidemiology; Male; Pennsylvania - epidemiology; Regression Analysis; Residence Characteristics; Los Angeles; Baltimore; Chicago; Pennsylvania
• ISSN: 0002-9262
• DOI: 10.1093/oxfordjournals.aje.a116094

The 5-year temporal trends in human immunodeficiency virus type 1 (HIV-1) seroconversion between 1984 and 1989 among homosexual/bisexual men participating in the Multicenter AIDS Cohort Study (MACS) are reported. Of 3,262 initially seronegative men, 368 (11.3%) had seroconverted by December 31, 1989. Although the incidence of seroconversion declined precipitously during the first 3 years of follow-up (from 4.1% to 0.9% per 6 months), no evidence for a further substantial reduction was noted after mid-1987, since 6-month incidence rates ranged between 0.5% and 1.2%. The Chicago cohort experienced an increase in HIV-1 seroconversion during both semesters of 1989; 2.1% and 1.6% per 6 months, respectively, became newly infected. Other MACS centers did not report such an increase. Center-specific differences were observed by race; black men were at higher seroconversion risk than white men in Baltimore/Washington (relative risk (RR) = 3.4) and Chicago (RR = 2.4), while Hispanic men were at higher risk than white men in Chicago (RR = 3.3). Younger age (less than 35 years) was also associated with HIV-1 seroconversion (RR = 1.5). It is disturbing to report an overall annual seroconversion rate of 1.2% for the 2 years prior to December 31, 1989, as well as evidence for a sustained recent increase in Chicago during 1989. Long-term maintenance of safe-sex behaviors should be the cornerstone of acquired immunodeficiency syndrome prevention among homosexual/bisexual men.