Use of antenatal clinic surveillance to assess the effect of sexual behavior on HIV prevalence in young women in Karonga district, Malawi.
BACKGROUND
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Department of Epidemiology and Public Health, London School of Hygiene and Tropical Medicine, London, United Kingdom. mia.crampin@lshtm.ac.uk
Amelia Catharine
AC
Crampin
Andreas
A
Jahn
Masiya
M
Kondowe
Bagrey M
BM
Ngwira
Joanne
J
Hemmings
Judith R
JR
Glynn
Sian
S
Floyd
Paul E
PE
Fine
Basia
B
Zaba
D000293:Adolescent; D000328:Adult; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000209:etiology; D006801:Humans; D008295:Malawi / Q000453:epidemiology; D011295:Prenatal Care; D015995:Prevalence; D012725:Sexual Behavior