Editing Chimpanzee (section)

===Human immunodeficiency virus===
Two primary classes of [[human immunodeficiency virus]] (HIV) infect humans: HIV-1 and HIV-2. HIV-1 is the more virulent and easily transmitted, and is the source of the majority of HIV infections throughout the world; HIV-2 occurs mostly in west Africa.<ref name="Reeves">{{cite journal |author=Reeves, J. D. |author2=Doms, R. W. |title=Human immunodeficiency virus type 2 |journal=The Journal of General Virology |volume=83 |issue=Pt 6 |pages=1253–65 |date=June 2002 |pmid=12029140 |doi=10.1099/0022-1317-83-6-1253 |url=http://vir.sgmjournals.org/cgi/pmidlookup?view=long&pmid=12029140 |archive-url=https://archive.today/20121228095942/http://vir.sgmjournals.org/cgi/pmidlookup?view=long&pmid=12029140 |archive-date=28 December 2012 |url-status=dead |citeseerx=10.1.1.523.5120}}</ref> Both types originated in west and central Africa, jumping from other [[Zoonosis|primates to humans]]. HIV-1 has evolved from a [[simian immunodeficiency virus]] (SIVcpz) found in the subspecies ''P. t. troglodytes'' of southern [[Cameroon]].<ref name="Keele">{{cite journal |last1=Keele |first1=B. F. |display-authors=etal |title=Chimpanzee reservoirs of pandemic and nonpandemic HIV-1 |journal=Science |volume=313 |issue=5786 |pages=523–526 |date=July 2006 |pmid=16728595 |pmc=2442710 |doi=10.1126/science.1126531 |bibcode=2006Sci...313..523K}}</ref><ref name="Gao">{{cite journal |last=Gao |first=F. |display-authors=etal |title=Origin of HIV-1 in the chimpanzee ''Pan troglodytes troglodytes'' |journal=Nature |volume=397 |issue=6718 |pages=436–41 |date=February 1999 |pmid=9989410 |doi=10.1038/17130 |bibcode=1999Natur.397..436G |s2cid=4432185|doi-access=free }}</ref> [[Kinshasa]], in the Democratic Republic of Congo, has the greatest genetic diversity of HIV-1 so far discovered, suggesting the virus has been there longer than anywhere else. HIV-2 crossed species from a different strain of HIV, found in the [[sooty mangabey]] monkeys in [[Guinea-Bissau]].<ref name="Reeves"/>