If lawyers get into heaven, Randy Shilts may soon face a libel suit from Gaeton Dugas, the Canadian flight attendant whose rep was ruined when Shilts dubbed him “Patient Zero” in And the Band Played On. That’s because scientists have finally fingered the original source of HIV—and it’s not Dugas, or the KGB, or Ronald Reagan. It’s the chimpanzee. Researchers have long suspected primates of HIV-infecting humans, but it wasn’t until last January’s Sixth Conference on Retroviruses that the simian culprit was cornered: a subspecies of chimp known as Pan Troglodytes Troglodytes, found in west equatorial Africa—the region where the first case of AIDS was identified. Lead researcher Beatrice Hahn, MD, of the University of Alabama at Birmingham, said the virus probably jumped the species barrier in the late ’40s or early ’50s, as a result of humans eating “bushmeat,” or chimp, still an African staple.

While HIV is relatively new to humans, chimps are thought to have carried their version of the virus—SIVcpv—for hundreds of thousands of years, with no apparent ill effects. Since chimps are 98 percent genetically identical to humans, scientists say that learning why those with SIVcpv don’t develop AIDS might eventually improve therapy and lead to a vaccine.

From Nightline to Nature, the media went bananas over the discovery: The Wall Street Journal said it solved “one of the most unsettling medical mysteries of the late 20th century.” But PWA Jeff Getty, who in 1995 successfully received a baboon marrow transplant, was underwhelmed: “It’ll be a long shot to replicate chimp immunity in humans,” he said. “There will never be a drug that makes us more chimp-like.” Hahn acknowledged that “HIV treatment and vaccine options are extremely hard to come by. But the chimp story opens a new door we can’t afford not to look behind, even if we ultimately find nothing there.”

Either way, there’s a setback to simian scrutiny: African “bushmeat traders” are slaughtering chimps at a quick clip. There are now only an estimated 150,000 in the wild. In an effort to preserve the species, the American Zoological Association has launched a campaign to humanize the chimp, thereby breeding a new set of values by which they’re too much like us to eat.