Epidemiology of HIV Infection in sub-Saharan Africa

Sub-Saharan Africa is the continent far most severely affected by the HIV pandemic accounting for more than 70% of all cases worldwide. More than 25 million Africans are now living with HIV, of whom 55% are women. The patterns of spread of HIV-1 and HIV-2 are highly dissimilar. In particular, the HIV-2 epidemic seems to have stabilized and may even be declining. In addition, the HIV-1 epidemic itself is geographicaly heterogeneous. In general, it is in southern Africa that the highest prevalence rates are observed among the general adult population. This review will discuss the multiple factors (host, virus, environment) that could explain this heterogeneous spread. AIDS is now the leading cause of death in Africa, with 2.4 million death per year. The dramatic demographic, social and economic consequences of such disaster are discussed.