1969: AIDS virus invaded U.S.

Study: AIDS virus invaded U.S. from Haiti in 1969

Excerpts:

They found that HIV was brought to Haiti by an infected person from central Africa in about 1966, which matches earlier estimates, and then came to the United States in about 1969.

The researchers think an unknown single infected Haitian immigrant arrived in a large city like Miami or New York, and the virus circulated for years -- first in the U.S. population and then to other nations.
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"That one infection would have become two, and then it doubles again and the two becomes four," Worobey said. "So you have a period -- probably a fair number of years -- where you're dealing with probably fewer than a hundred people who are infected.

"And then, as with epidemic expansion, at some point the hundred becomes 200, you start getting into thousands, tens of thousands. And then quite rapidly you can be up into the hundreds of thousands of infections that were probably already there before AIDS was recognized in the early 1980s."
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Studies suggest the virus first entered the human population in about 1930 in central Africa, probably when people slaughtered infected chimpanzees for meat.