title: Temporal trends in human immunodeficiency virus type 1 seroconversion 1984-1989. A report from the Multicenter AIDS Cohort Study (MACS).
abstract: 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.
authors.affiliation: Department of Infectious Diseases, Graduate School of Public Health, University of Pittsburgh, PA.
authors.forename: L A
authors.initials: LA
authors.lastname: Kingsley
authors.forename: S Y
authors.initials: SY
authors.lastname: Zhou
authors.forename: H
authors.initials: H
authors.lastname: Bacellar
authors.forename: C R
authors.initials: CR
authors.lastname: Rinaldo
authors.forename: J
authors.initials: J
authors.lastname: Chmiel
authors.forename: R
authors.initials: R
authors.lastname: Detels
authors.forename: A
authors.initials: A
authors.lastname: Saah
authors.forename: M
authors.initials: M
authors.lastname: VanRaden
authors.forename: M
authors.initials: M
authors.lastname: Ho
authors.forename: A
authors.initials: A
authors.lastname: Muñoz
mesh_terms: D000367:Age Factors; D015142:Baltimore / Q000453:epidemiology; D001727:Bisexuality; D002641:Chicago / Q000453:epidemiology; D015331:Cohort Studies; D006679:HIV Seropositivity / Q000453:epidemiology*; D015528:HIV Seroprevalence; D015497:HIV-1; D006716:Homosexuality; D006801:Humans; D015994:Incidence; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D010414:Pennsylvania / Q000453:epidemiology; D044469:Racial Groups; D012044:Regression Analysis; D012111:Residence Characteristics