Temporal trends in human immunodeficiency virus type 1 seroconversion 1984-1989: A report from the multicenter AIDS cohort study (macs)

Lawrence A. Kingsley, Susan Y.J. Zhou, Helena Bacellar, Charles R. Rinaldo, Joan Chmiel, Roger Detels, Alfred Saah, Mark Vanraden, Monto Ho, Alvaro Muñoz

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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 (<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.

Original languageEnglish (US)
Pages (from-to)331-339
Number of pages9
JournalAmerican journal of epidemiology
Issue number4
StatePublished - Aug 15 1991



  • Acquired immunodeficiency syndrome
  • HIV
  • HIV seropositivity
  • HIV seroprevalence

ASJC Scopus subject areas

  • Epidemiology

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