Sexual behaviour patterns in South Africa and their association with the spread of HIV: insights from a mathematical model

This paper aims to quantify the effects of different types of sexual risk behaviour on the spread of HIV in South Africa. A mathematical model is developed to simulate changes in numbers of sexual partners, changes in marital status, changes in commercial sex activity, and changes in the frequency of unprotected sex over the life course. This is extended to allow for the transmission of HIV, and the model is fitted to South African HIV prevalence data and sexual behaviour data. Results suggest that concurrent partnerships and other non-spousal partnerships are major drivers of the HIV/AIDS epidemic in South Africa.