CONCISE COMMUNICATION Determinants and prevalence of HIV infection in pregnant Peruvian women Jorge O. Alarcon a , Kay M. Johnson b,c,d , Barry Courtois c , Carlos Rodriguez e , Jorge Sanchez f , Douglas M. Watts g , King K. Holmes b,c Objectives: To determine age-specific seroprevalence, risk factors, and risk markers for heterosexually-acquired HIV infection among pregnant women. Design: Cross-sectional study of 12436 consecutive pregnant women in Lima, Peru in 1996–1997. Methods: Standardized interviews, serologic tests for HIV and syphilis, bivariate and multivariate analysis. Results: HIV seropositivity was confirmed in 58 women (0.5%). Only 22.6% were married, and only 12% of HIV infected women reported >2 sex partners ever. In multivariate analyses HIV infection was associated with: short duration of current relationship; two risk behaviors of women themselves (early onset of sexual activity and number of past sexual relationships); women’s perceptions of two risk behaviors of partners (partner is a ‘womanizer,’ and partner uses illegal drugs); inadequate prenatal care; and four additional risk factors or markers (history of sexually trans- mitted disease, tuberculosis, or abortion in the women; and diagnosis of HIV/AIDS in a partner). Conclusions: HIV infection was related both to women’s own risk behaviors and to the perceived risk behaviors of their sexual partners. Underlying societal factors related to heterosexual HIV infection, including deferral of marriage, warrant further study. & 2003 Lippincott Williams & Wilkins AIDS 2003, 17:613–618 Keywords: heterosexual transmission, risk factors, sexual behavior, South America Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited. From the a Tropical Medicine Institute of Universidad Nacional Mayor De San Marcos, Lima, Peru, the b Departments of Medicine and Epidemiology, the c Center for AIDS & STD, University of Washington, the d VA Puget Sound Health Care System, Seattle, Washington, USA, the e Instituto Materno-Perinatal de Lima, Lima, Peru, the f Program for AIDS and STD, Ministry of Health, Lima, Peru, and the g US Navy Medical Research Center, Lima, Peru. Correspondence to K. M. Johnson, Veterans Affairs Puget Sound Health Care System, Mailstop 111WOM, 1660 South Columbian Way, Seattle, WA 98108, USA. Note: Presented in part in the Bulletin of the Instituto Materno Perinatal de Lima. Received: 9 July 2001; revised: 9 May 2002; accepted: 30 September 2002. DOI: 10.1097/01.aids.0000042973.95433.22 ISSN 0269-9370 & 2003 Lippincott Williams & Wilkins 613