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Traced: The Origins of the Aids Epidemic in America

Posted on : 2007-10-30

An international team of scientists has revealed in the US National Academy of Sciences that the strain of the HIV virus which was the scourge of the United States and Europe in the 1970s and 1980s in all probability originated in the Caribbean island of Haiti. It was brought to American shores sometime around 1969 and thereafter spread to other countries. It took about twelve years for AIDS to be recognized in 1981.

The scientists had focused on a variety of HIV known as subtype B, which is prevalent most countries outside Africa, and found a 99.7% certainty that it had originated in Haiti.

In the course of their study they analyzed HIV DNA saved 25-years earlier in 1982-1983 from five people who were among the first recognized AIDS patients and who had all emigrated from Haiti to Miami.

As a baseline, they analyzed and used another 117 virus samples from Central Africa that are considered some of the earliest forms of the human immunodeficiency virus as well as samples from other parts of the world.

The team discovered that the Haitian samples and the African virus were the most closely related genetically pointing to the probability that they were among the earliest to branch.

They used this information to construct a family tree for the virus and they believe this allays any doubts of that the strain coming to the United States from Haiti. They believe it to be possible that one person was responsible for bringing the strain over somewhere around 1969.

The strain of the virus that became an epidemic in the US also spread to Canada, Europe, Australia, and Japan.

"Once the virus got to the US, then it just moved explosively around the world," Worobey said

Previous knowledge of the virus' migration has been only vaguely traced from its origin in Africa in the 1930s to when it was first detected in Los Angeles in 1981.

Assistant clinical professor of medicine at UCLA, Dr. Michael Gottlieb, who was one of the discoverers of acquired immune deficiency syndrome, stated that the study placed the virus in the United States nearly ten years earlier than had been previously believed.

"It's pretty clear evidence for Haiti as a steppingstone. The suggestion that the infection was further below our radar than I'd previously suspected is kind of unnerving," he is reported to have said.

The scientists hope that this knowledge will be instrumental in finding a cure for HIV and ultimately for AIDS.

One of the study's authors and evolutionary biologist, Michael Worobey from Tucson's University of Arizona and team now aim to trace the roots of the strain even further. He suspects that it most likely was brought to Haiti from the Democratic Republic of Congo, formerly Zaire, by Haitians working in Africa at that time.

The professor believes that understanding the genesis of this particular strain as well as those of other strains would allow scientists to accurately envisage its future modes of mutation.

Robert Garry, a microbiologist at Tulane University remarked, "The findings are significant,” and continued that they indicated "an important lineage of subtype B HIV was present in Haiti, which eventually spread elsewhere."

However he does not believe that a Haitian origin is the only explanation for subtype-B strains in the Americas, but thinks it quite possible that other B lineages made their appearance in the Americas before this and were most probably independent of the Haitian strain.