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 area, 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 sex 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.
PIP: A population-based cross-sectional study conducted in northern Tanzania's Arusha region found women to be at even greater risk of human immunodeficiency virus (HIV) infection than men. Three diverse sites--Unga limited (urban), the town of Babati (semi-urban), and the roadside village of Matufa (rural)--were selected. 862 (567 women and 295 men) out of 2216 eligible respondents both completed a questionnaire and provided a blood sample for HIV testing. Overall HIV-1 seroprevalence was significantly higher for women (8.5%) than men (2.0%), with a range from 2.3% among women in the rural village of Matufa to 14.4% among urban women in Unga limited. Marital status, occupation, age at first intercourse, educational status, religion, and travel within the Arusha region were not associated with a significant increase in HIV infection; however, travel out of the region or out of Tanzania was a significant risk factor. Also significant was having two or more sexual partners in the last six months or past five years. Finally, HIV rates were significantly higher among women who used condoms and those who had sexual intercourse under the influence of alcohol. The high HIV seroprevalence rate identified in this study among women may reflect selection bias and other potential risk factors (e.g., previous history of sexually transmitted diseases) that were not assessed. Of particular concern is the likelihood, given condom use as an HIV risk factor, that condoms are being used incorrectly or inconsistently in this population. Since Tanzanian women lack power in sexual relations, HIV/AIDS preventive interventions must target men as well as women.