Sooty mangabey

The sooty mangabey ("Cercocebus atys"), is an Old World monkey of Guinea Bissau, Gabon, Senegal and Ghana. It has social groups of four to twelve individuals.
Disease.
Sooty mangabeys are naturally infected with a strain of Simian Immunodeficiency Virus (SIV). Due to extensive human-mangabey contact in sub-Saharan Africa, the virus has jumped from this species into humans on many occasions. This resulted in the HIV-2 virus. The HIV-1 strain by contrast came from the common chimpanzee strain of SIV.
The sooty mangabey can also get leprosy, as can humans, the Nine-banded Armadillo, the common chimpanzee, and the crab-eating macaque.