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
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
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.
The authors declare no conflict of interest.
This article is a PNAS Direct Submission.
Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. EF159970–EF159974 and EF362773–EF362777).
See Commentary on page 18351.
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.
Freely available online through the PNAS open access option.
- © 2007 by The National Academy of Sciences of the USA
