I missed this yesterday and perhaps everyone has already seen it, but this made my jaw drop for several reasons. First, that scientists were able to put the pieces together to make this conclusion. That is just staggering to me. Second, so much horror came from that single source is more than I can comprehend. I’ve known, as we all have, about a ‘patient zero’ but somehow this news makes it that much more… horrifying.

The AIDS virus invaded the United States in about 1969 from Haiti, carried most likely by a single infected immigrant who set the stage for it to sweep the world in a tragic epidemic, scientists said on Monday.
Michael Worobey, a University of Arizona evolutionary biologist, said the 1969 U.S. entry date is earlier than some experts had believed.
The timeline laid out in the study led by Worobey indicates that HIV infections were occurring in the United States for roughly 12 years before AIDS was first recognized by scientists as a disease in 1981. Many people had died by that point.
“It is somehow chilling to know it was probably circulating for so long under our noses,” Worobey said in a telephone interview.
The researchers conducted a genetic analysis of stored blood samples from early AIDS patients to determine when the human immunodeficiency virus first entered the United States.
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.