The HIV/AIDS epidemics of Africa

The global pandemic of HIV-1 began in Africa, perhaps as many as 75 years ago, in a complex series of species cross-overs involving the original old world monkey hosts of this class of viruses, and subsequently our closest relatives, the Chimpanzees, and then ourselves. In an unfortunate connection with our Chimp cousins, it appears that Chimps were likely exposed to these viruses through the hunting and eating of monkeys, and humans in turn, through the hunting, butchering, and ingestion of Chimps (Wolfe et al., 2007; Keele et al., 2006.) HIV-2, the second virus which causes HIV/AIDS, probably emerged from a distinct cluster of monkey species from HIV-1. Though it causes an essentially identical clinical AIDS syndrome as does HIV-1, the period from infection to clinical disease is generally years longer for HIV-2. A much less infectious virus for humans, HIV-2 has to date remained limited principally to outbreaks in West Africa and in India, and is discussed in the West Africa chapter by Blattner, et al. It is HIV-1 which has found global "legs" and reached communities from the Amazon to Siberia, to Haiti and China, Havana, Paris, Lagos and Prague.