The AIDS virus entered the United States via Haiti, probably arriving in just one person in about 1969, earlier than previously believed, according to new research.
After the virus, HIV-1, entered the U.S., it flourished and spread worldwide.
"Our results show that the strain of virus that spawned the U.S. AIDS epidemic probably arrived in or around 1969. That is earlier than a lot of people had imagined," said senior author Michael Worobey.
The research is the first to definitively pinpoint when and from where HIV-1 entered the United States and shows that most HIV/AIDS viruses in the U.S. descended from a single common ancestor. The actual ancestral HIV entered the U.S. long before the storied "Patient Zero," Worobey said.
"Haiti was the stepping stone the virus took when it left central Africa and started its sweep around the world," said Worobey, an assistant professor of ecology and evolutionary biology at The University of Arizona in Tucson. "Once the virus got to the U.S., then it just moved explosively around the world."
The strain that migrated to the U.S. in 1969, HIV-1 group M subtype B, is the first human immunodeficiency virus discovered. It is the dominant strain of the AIDS virus in most countries outside sub-Saharan Africa. Almost all the viruses in those countries descended from the one that emerged from Haiti, he said.
Worobey and his colleagues figured out when HIV reached the U.S. by conducting genetic analyses of archived blood samples from early AIDS patients.
Learning more about the genetic make-up of the various strains of HIV could help vaccine development, Worobey said.
The scientists' research paper, "The emergence of HIV/AIDS in the Americas and beyond," is scheduled for publication in the online Early Online edition of the Proceedings of the National Academy of Sciences the week of October 29.
Worobey's co-authors are M. Thomas P. Gilbert of
|Contact: Mari N. Jensen|
University of Arizona