The relationship between HIV and associated behaviour, and population traits that drive the epidemic, vary from district to district in South Africa. Looking at the eight metros, the City of Tshwane had the lowest HIV prevalence while Ekurhuleni had the highest. The city of Cape Town and Nelson Mandela also had lower HIV occurrences.

Those districts with high HIV prevalence have very homogeneous populations, defined by characteristics such as black African, a high proportion of unmarried or single females, low socio-economic status, multiple sexual partners and sexual relationships between different generations (intergenerational sex).

In a study, published in the latest edition of the peer-reviewed scientific journal, Spatial and Spatio-temporal Epidemiology, Njeri Wabiri et al drilled down to district level to establishing how the relationship between HIV and behavioural factors change from location to location.

The study, conducted by a research team at the Human Sciences Research Council, is a further analyses of the 2008 South African National HIV Prevalence, Incidence, Behaviour and Communication Survey, which comprised 23 369 randomly selected participants from approximately 1000 enumeration areas. The study analysed data from the 52 municipal districts in South Africa, which is the channel through which basic primary health care is delivered.

Dr Njeri Wabiri, a statistician and chief research manager of the HIV/AIDS, STIs and TB Programme at the HSRC explains: ‘We used geographical information systems modelling to generate maps that show the difference in spatial relationship between observed local patterns of HIV prevalence and what are the behavioural patterns that drive HIV across South Africa’.

These findings are significant, says Wabiri, as it indicates the need for additional localised research to ascertain other important social, behavioural, and biological drivers of HIV infection. This is of particular value for the government’s HIV and AIDS strategy to identify and to focus on ‘HIV hotspots’ – those areas that have exceptional high HIV occurrence.

She says markedly, intergenerational sex compounds the risk of acquiring HIV infection for females in poor districts.

Dr Olive Shisana, the second author and former CEO of the HSRC, said by identifying key social drivers of HIV and how they vary from district to district, can help to effectively guide and focus intervention programmes to areas of particular need.

But there are still many questions that need to be answered, says Wabiri, such as the  anti-retroviral treatment rates at the district level and how do these relate to changes in prevalence rates; establishing the major differences in behaviour patterns in rural and informal settlements in areas where HIV prevalence remains low in spite of high numbers of settlements; and whether  these differences in behaviour account for differences in HIV prevalence and can these behaviours inform prevention strategies more broadly.

Note to editors:
To obtain the full article or for interviews, e-mail Ina van der Linde at  ivdlinde@hsrc.ac.za, or call 0823310614.