The Uneven Spread of HIV within Africa: A Comparative Study of Biological, Behavioral and Contextual Factors in Rural Populations in Tanzania and Zimbabwe

Ties Boerma, University of North Carolina at Chapel Hill
Constance Nyamukapa, Biomedical Research & Training Institute
Mark Urassa, TANESA project
Simon Gregson, Wellcome Trust Centre for the Epidemiology of Infectious Disease

Available data on HIV prevalence in sub-Saharan Africa indicate large heterogeneity in the spread of HIV across the continent. This analysis focuses on the comparison of two populations in rural Africa for which extensive data are available: rural Kisesa in northwest Tanzania and rural Manicaland in eastern Zimbabwe. HIV prevalence levels among the adult population are three times higher in Zimbabwe. The comparative analysis of a wide range of biological, behavioral and contextual indicators resulted in a few possible reasons for the much higher HIV transmission in Zimbabwe. Later marriage, lower levels of cohabitation of marital partners and higher levels of mobility, lack of male circumcision, and possibly higher incidence of HSV-2 are possible reasons. On the other hand, there were at least as many results that suggested that HIV transmission should be lower in Manicaland compared to Kisesa, especially in association with reported sexual behavior.