Objectives:To assess whether differences in age between sexual partners affect the risk of HIV infection in female adolescents and young adults.
Methods:A total of 6177 ever sexually active women aged 15 to 29 years completed a sociodemographic and sexual behavior questionnaire and provided a blood sample for HIV-1 serology. The age difference between partners was categorized as men 0 to 4 years older (referent group), 5 to 9 years older and 10 or more years older. HIV prevalence and incidence were assessed, and adjusted RR was estimated by multivariate regression.
Results:Prevalent HIV-1 infection in female participants increased with older male sexual partners. Among women aged 15 to 19 years, the adjusted risk of HIV infection doubled (RR = 2.04; 95% CI: 1.29-3.22) among those reporting male partners 10 or more years older compared with those with male partners 0 to 4 years older; among women 20 to 24 years of age, the RR was 1.24 (95% CI: 0.96-1.60). The attributable fraction (exposed) of prevalent HIV infection in women aged 15 to 24 years associated with partners 10 or more years older was 9.7% (95% CI: 5.2-14.0). HIV incidence did not increase with differences in age of partners.
Conclusion:The age difference between young women and their male partners is a significant HIV risk factor, suggesting that high HIV prevalence in younger women is caused, in part, by transmission from older male partners.
The study was supported by grants F31 AI10288-01, RO1 AI34826, and RO1 AI34826S from the National Institute of Allergy and Infectious Diseases, grant 5P30HD06826 from the National Institute of Child Health and Development of the U.S. National Institutes of Health, the Rockefeller Foundation, and the World Bank Uganda STI Project. Selected drugs and laboratory tests were provided by Pfizer, Abbott Laboratories, Roche Molecular Systems, and the Calypte Biomedical Corporation.
Address correspondence and reprint requests to Ronald H. Gray, Room 4030, School of Hygiene and Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205. U.S.A.; e-mail: firstname.lastname@example.org.
Manuscript received January 30, 2002; accepted November 13, 2002.
© 2003 Lippincott Williams & Wilkins, Inc.