Searching for the epidemic's origins.

ABSTRACT

Theories about the origin of AIDS all suffer from a dearth of data. For more than a decade, researchers have recognized the close genetic links between SIV from sooty mangabeys and HIV-2, a type of the virus that is mostly confined to west African countries, but to date, there are scant data that closely link HIV-1, the predominant human AIDS virus, to SIVs found in primates.