Risk factors for HIV-1 infection among women were assessed through a population-based cross-sectional study in the Arusha region of northern Tanzania. The study participants were obtained by randomly selecting 10-household clusters from Unga limited, the town of Babati, and the roadside village of Matufa, which are urban, semi-urban, and rural communities, respectively. Informed verbal consent for participation in an interview and in HIV-1 testing was sought from each respondent. Blood samples were collected from each consenting individual for HIV-1 antibody testing using enzyme-linked immunosorbent assay (ELISA), and all positive sera were confirmed using repeated ELISA tests. Information of risk factors was obtained through the interview process using a structured questionnaire. Of the 567 women who gave blood samples, 48 (8.5%) were HIV-1 positive. The HIV-1 seroprevalence rates among women in the urban area, the semi-urban areal and the rural village were 14.4%, 6.9%, and 2.3%, respectively. Factors associated with significantly higher HIV-1 seroprevalence were urban residence; history of having traveled out of the Arusha region within Tanzania, as well as having traveled abroad; having multiple sexual partners; and having sexual intercourse under the influence of alcohol. Women who reported ever having used condoms had significantly higher probability of being infected with HIV-1 than those who had never used condoms, suggesting that condom use may be a marker of high-risk sexual behavior and that condom use is probably not adhered to in a way that consistently protects against HIV-1 infection. These results suggest the need for health education interventions aimed at increasing appropriate and consistent condom use and reduction of the number of sexual partners.
