OBJECTIVE

To examine changes in sexual behaviour among men in urban Tanzania.

DESIGN

An observational cohort study among factory workers during 1991-1994.

METHODS

Data from five follow-up visits with structured questionnaire-guided interviews and biomedical data were analysed to examine trends in sexual behaviour and sexually transmitted disease/HIV among 752 men. In-depth interviews were conducted to evaluate the magnitude of reporting bias.

RESULTS

During the 2 years of observation, the proportion of men with more than one sexual partner during the month preceding the interview declined from 22.3 to 12.2%. The proportion of men reporting casual sex partners during the last month was almost halved: from 9.8 to 5.2%. The decline in the reporting of extramarital partners was gradual and pronounced. There were only minor changes in reported condom use, notably an increase in use with casual partners, and no changes in coital frequency. Data from in-depth interviews confirmed that reduction in sexual partners was the predominant change.

CONCLUSIONS

This study documents that, in response to the AIDS epidemic, changes in male sexual behaviour are taking place in urban areas in Africa. The predominant change among these men, who are predominantly married and aged over 25 years, is a reduction of the number of sexual partners, although condom use remains low.