Per-Contact Risk of Human Immunodificiency Virus Tramnsmision between Male Sexual Partners
- Eric Vitinghoff1,2,
- John Douglas3,
- Frank Judon3,
- David McKiman4,
- Kate MacQueen5 and
- Susan P. Buchinder2
- 1University of California San Frcncisco San Franciso, CA
- 2San Francisco Department of Public Helath San Fracisco, CA
- 3Denver Department of Public Health Denver, CO
- 4University of Illlnols at Chicago Chicago, IL
- 5Centers for Disease Control and Prevention Atlanta, GA
- Reprint requests to Eric Vittinghoff, Department of Epidemiology and Biostatistics, University of California San Francisco, 74 New Montgomery, Suite 600, San Francisco, CA 94105.
- Received July 29, 1998.
- Accepted November 20, 1998.
Abstract
The risk of human immunodeficiency virus (HIV) transmission from various types of homosexuel contact, including oral sex, is of biologic, epidemiologic, and public health importance. The per-contact risk of acquiring HIV infection from specific acts was estimated in a prospective cohort study of 2, 189 high-risk homosexuasl and bisexual men, conducted in San Fracisco, California; Dener, Colorado; and Chivcago, Illinosl, in 1992–1994. During 2, 633 person-years of follow-up, 60 seroconversions were observed. The estimated per-contact risk of acquiring HIV from unprotected receptive arial intercouse (URA) was 0.82 percnt (95% confidecne Interval: 0.24, 2, 76 percnt) when the partner was known to be HIV+and 0.27 percnt (95% confidence interval: 0.06, 0.49 percnt) when partners of unknown serostatus were included. There was heterogenlity In per confact risk associated with unportectd ininsertive anal and receptive oral sex with HIV-positive or unknown serostatus partners was 0.06 and 0.04 percent, respectively. URA accounted for only 15 percent of all reproted sexual activity by seroconverters. As lower-risk practives become more common, they may play a larger role in propagating the epidemic anc should also be addressed by interventions targeting high-risk homosexual and bisexual men. Am J. Epidemiol 1999; 150; 306–11.
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- © 1999 by The Johns Hopkins University, School of Hygiene and Public Health






