Antenatal clinic (ANC) surveillance is the primary source of HIV prevalence estimates in low-resource settings. In younger women, prevalence approximates incidence. Sexual behavior monitoring to explain HIV distribution and trends is seldom attempted in ANC surveys. We explore the use of marital history in ANC surveillance as a proxy for sexual behavior.
Five ANC clinics in a rural African district participated in surveillance from 1999 to 2004. Unlinked anonymous HIV testing and marital history interviews (including age at first sex and socioeconomic variables) were conducted. Data on women aged <25 years were analyzed.
Inferred sexual exposure before marriage and after first marriage increased the adjusted odds of infection with HIV by more than 0.1 for each year of exposure. Increasing years within a first marriage did not increase HIV risk. After adjusting for age, women in more recent birth cohorts were less likely to be infected.
Marital status is useful behavioral information and can be collected in ANC surveys. Exposure in an ongoing first marriage did not increase the odds of infection with HIV in this age group. HIV prevalence decreased over time in young women. ANC surveillance programs should develop proxy sexual behavior questions, particularly in younger women.
From the *Department of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine, London, United Kingdom; and the †Karonga Prevention Study, Malawi, Africa.
Received for publication October 4, 2007; accepted March 3, 2008.
Correspondence to: Amelia Catharine Crampin, MBChB, MSc, Department of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine, Keppel, London, WC1E 7HT United Kingdom (e-mail: firstname.lastname@example.org).