Some aspects of sexual behaviour and the potential demographic impact of AIDS in developing countries.

This review examines recent research on the influence of heterogeneity in sexual behaviour on the transmission dynamics of the human immunodeficiency virus (HIV), the aetiological agent of AIDS. Attention is focused on the potential demographic impact of AIDS in developing countries and how this is influenced by the structure of networks of sexual contacts (who mixes with whom), age-dependency in rates of sexual partner change and differences in the ages of female and male sexual partners. Analyses based on the construction of simple and complex mathematical models of the spread of HIV via heterosexual contact serve as a template for the interpretation of observed pattern and as a guide to the major aspects of sexual behaviour that govern the transmission dynamics of the virus. It is argued that much greater attention must be addressed to the quantification of patterns of sexual behaviour in defined communities, despite the many practical problems that surround data collection and interpretation.