The emergence of HIV/AIDS in the Americas and beyond
- M. Thomas P. Gilbert*,†,
- Andrew Rambaut‡,
- Gabriela Wlasiuk*,
- Thomas J. Spira§,
- Arthur E. Pitchenik¶, and
- Michael Worobey*,‖
- *Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721;
- †Ancient DNA and Evolution Group, Centre for Ancient Genetics, Niels Bohr Institute and Biological Institute, University of Copenhagen, DK-2100 Copenhagen, Denmark;
- ‡Institute for Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom,;
- §Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, GA 30333; and
- ¶Department of Medicine, University of Miami, Miami, FL 33125
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Edited by John M. Coffin, Tufts University School of Medicine, Boston, MA, and approved September 17, 2007 (received for review June 6, 2007)
Abstract
HIV-1 group M subtype B was the first HIV discovered and is the predominant variant of AIDS virus in most countries outside of sub-Saharan Africa. However, the circumstances of its origin and emergence remain unresolved. Here we propose a geographic sequence and time line for the origin of subtype B and the emergence of pandemic HIV/AIDS out of Africa. Using HIV-1 gene sequences recovered from archival samples from some of the earliest known Haitian AIDS patients, we find that subtype B likely moved from Africa to Haiti in or around 1966 (1962–1970) and then spread there for some years before successfully dispersing elsewhere. A “pandemic” clade, encompassing the vast majority of non-Haitian subtype B infections in the United States and elsewhere around the world, subsequently emerged after a single migration of the virus out of Haiti in or around 1969 (1966–1972). Haiti appears to have the oldest HIV/AIDS epidemic outside sub-Saharan Africa and the most genetically diverse subtype B epidemic, which might present challenges for HIV-1 vaccine design and testing. The emergence of the pandemic variant of subtype B was an important turning point in the history of AIDS, but its spread was likely driven by ecological rather than evolutionary factors. Our results suggest that HIV-1 circulated cryptically in the United States for ≈12 years before the recognition of AIDS in 1981.
Footnotes
- ‖To whom correspondence should be addressed. E-mail: worobey{at}email.arizona.edu
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Author contributions: M.T.P.G., A.R., and M.W. designed research; M.T.P.G., A.R., and M.W. performed research; T.J.S. and A.E.P. contributed new reagents/analytic tools; A.R., G.W., T.J.S., A.E.P., and M.W. analyzed data; and A.R. and M.W. wrote the paper.
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The authors declare no conflict of interest.
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This article is a PNAS Direct Submission.
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Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. EF159970–EF159974 and EF362773–EF362777).
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See Commentary on page 18351.
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This article contains supporting information online at www.pnas.org/cgi/content/full/0705329104/DC1.
- Abbreviations:
- TMRCA,
- time of the most recent common ancestor;
- MCMC,
- Markov chain Monte Carlo.
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Freely available online through the PNAS open access option.
- © 2007 by The National Academy of Sciences of the USA
