The Structure of Sexual Networks and the Spread of HIV/AIDS in Rural Malawi

Stephane Helleringer, University of Pennsylvania
Hans-Peter Kohler, University of Pennsylvania

Studies of the role of sexual networks in fostering the spread of HIV in Sub-Saharan Africa have usually relied on data from individual-centered surveys and local network designs. In this paper, however, we report analyses using complete population data on the sexual networks of approximately 700 young adults living in two villages of Malawi. Precise images and measures of network structure are derived from reports of relationships gathered during computer-assisted interviews. The study also includes the collection of biomarkers of HIV infection, and thus enables us to describe in detail the position of HIV-infected individuals within these sexual networks. Using this unique dataset, we empirically explore the role of connectivity patterns in explaining the “uneven spread” of HIV across communities in Sub-Saharan Africa. We also draw some of the implications of the observed network structures for the design of programs aimed at preventing the diffusion of HIV.