Patterns of sexual behaviour in a rural population in north-western Tanzania

The HIV epidemic in sub-Saharan Africa has been characterised by the predominance of heterosexual transmission. Patterns of sexual behaviour have been implicated in the spread of the epidemic, but few quantitative data are available on sexual behaviour in rural populations in Africa. This paper reports data from a survey of 1117 adults aged 15-54 years selected randomly from twelve rural communities in Mwanza Region, Tanzania. Sexual debut occurred early, 50% of women and 46% of men reporting first sex before age 16. On average, women married 1.8 years and men 6.1 years after their sexual debut. In women, age at sexual debut appears to have increased over time, in parallel with an increase in age at first marriage. Men were generally married later, to women around five to ten years younger than themselves. Marital dissolution and remarriage were common in both sexes. Reported numbers of sexual partners were compared with those recorded in a population survey in Britain. More men reported 10 or more lifetime partners, or three or more partners in the past year, in rural Mwanza (48% and 29%) than in Britain (24% and 6%). Women reported fewer partners, and results were broadly similar to British data. Casual sex during the past year was reported by 53% of the men and 15% of the women, but only 2% of men reported sexual contact with bar girls or commercial sex workers. Only 20% of men and 3% of women had ever used a condom. Interventions are needed to reduce the high levels of sexual partner change and casual sex, and low levels of condom use, recorded in this rural population. Targeting of interventions to traditional "core groups" may be of limited value in rural areas, and additional strategies are needed, focusing particularly on teenagers who are at high risk of HIV and other sexually transmitted diseases.