AIDS Stopped in Haiti Before U.S.

By Randy Dotinga
HealthDay Reporter
Wednesday, October 31, 2007; 12:00 AM

Copyright © 2007 ScoutNews, LLC. All rights reserved.

TUESDAY, Oct. 30 (HealthDay News) -- New research into the genetic history of HIV suggests that the virus that causes AIDS stopped in Haiti during the middle of the last century, prior to reaching the United States.

The findings are unlikely to help scientists discover better treatments for AIDS, but they could provide insight into how HIV evolves and moves from place to place, said Michael Worobey, a professor in the University of Arizona's Department of Ecology and Evolutionary Biology and co-author of a study released Monday.

"It matters when these events occurred and how often colonizations of new locales occur," he said. "That helps us predict the future complexity of the HIV pandemic."

The study findings about the spread of HIV are "definitive," added Dr. Beatrice Hahn, a professor in the University of Alabama at Birmingham's departments of medicine and microbiology. Hahn, who studies how the virus developed, said the next step in research is to go "further back in time" and use old blood samples from central Africa to understand more about the early days of AIDS.

Scientists are certain that the AIDS virus developed somewhere in Africa after a virus jumped from monkeys to humans. But there are still questions about the history of HIV and how it incubated in Africa before moving on to the rest of the world.

In the new study, Worobey and colleagues studied a strain of the AIDS virus known as subtype B, which commonly affects people in many countries, including the United States. The researchers tried to figure out how the virus traveled by studying blood samples of Haitian immigrants to the United States who were among the first in the country to be diagnosed as suffering from AIDS.

"For the last few years, we've been thinking it would be good to try to collect and analyze as many archival human samples as possible," Worobey said. "We can travel back in time and look directly at the viruses that were circulating at early time points."

The findings were published this week in an online edition of the Proceedings of the National Academy of Sciences.