Haunted By HIV’s Origins

Michael Worobey, an evolutionary biologist at the University of Arizona, is a nice guy—not the sort to seek out international controversy. But last week he found himself deluged with angry e-mails, and the Haitian Embassy and Consulates across the country were fielding hundreds of equally irate phone calls about him. Biology papers don't usually stir up so much fury. But Worobey's latest research, published in the Proceedings of the National Academy of Sciences, tracks the spread of HIV and suggests that the most common Western strain first hitchhiked its way to America around 1969 in the body of a single person—a person who almost certainly contracted the disease in Haiti.

Worobey says "Haitians are blameless for the spread of HIV. They were simply hit earlier." But a lot of Haitians feel offended anyway. Many of HIV's early victims in the West were Haitian immigrants, a link that led to "an adverse immigration policy in the United States and feelings of persecution and denial," writes Dr. Arthur Fournier in the 2006 book "The Zombie Curse." Now Haitians fear another wave of discrimination, and they're loath to believe Worobey's conclusions. "How do we know that a homosexual infected in America didn't bring HIV to Haiti instead?"  asks Raymond Joseph, the Haitian ambassador to the United States.

The new data show the chances of that scenario are "virtually nil," Worobey says. He has analyzed mutations over time in the virus, constructing a family tree for the different strains. And the tree tells him with "greater than 99 percent certainty" that HIV migrated from Africa to Haiti before it moved on to the United States. One person evidently brought the "subtype B" strain from Haiti to the United States in or around 1969. Almost all the strains found in the West today descend from that lone, unwitting patient.

The study has implications beyond Haiti. For one thing, it's now clear that "Patient Zero"—Gaetan Dugas, who slept with more than 2,500 people before dying in 1980—was almost certainly not the real Patient Zero. It also sheds new light on the earliest possible cases of AIDS in America. Some forms of HIV were quietly circulating here before 1969, and they "probably made several attempts" at spreading widely, says Dr. Beatrice Hahn, an HIV researcher at the University of Alabama at Birmingham. But "for whatever reason, those did not spawn an epidemic." If only the one from 1969 hadn't, either.