An HIV Genome from Two Decades Before Its Discovery
theatlantic.com
theatlantic.com
>Dr. Pépin calculates that, in the early 1920s, a maximum of 1,350 hunters might have had blood-to-blood contact with troglodytes chimps. Only 6 percent of the chimps — about 80 — would have been infected, and fewer than 4 percent of the scratched hunters probably could have caught it. That would suggest only three infected hunters at most.
> Given how inefficient most sexual spread is — in some cases, a husband and wife can have sex for months without passing H.I.V. — sex alone would not have let three hunters, or even a dozen, pass on their virus to today’s millions, he argues. There must have been an amplifier.
> In the 1920s, machine-made glass syringes replaced expensive hand-blown ones, and the Belgians and French attacked many diseases in their colonies, both out of paternalism and to create herd immunity to protect whites. Patients might get up to 300 shots in a lifetime. Other diseases have spread this way; an Egyptian campaign against schistosomiasis ended in 1980 after giving more than half its “beneficiaries” hepatitis C.
> And, in one of his own studies of elderly Africans, Dr. Pépin was told that many of those injected against sleeping sickness in the 1940s had died in the 1950s. Since many of the survivors were infected with HTLV, another chimp virus, he surmised that their long-dead friends might have been among the first victims of AIDS.
> Haiti’s epidemic, like that of North America and Western Europe, is nearly all subgroup B. But subgroup B is so rare in central Africa that it causes less than 1 percent of cases.
> That suggests AIDS crossed the Atlantic in just one Haitian. Molecular clock dating indicates it reached Haiti roughly in 1966.