Chimpanzees in the wild can die from an AIDS-like virus, according to a new study that defies current scientific thinking.
African animal primates are infected with more than 40 different strains of simian immunodeficiency virus or SIV. Two of these strains spread to humans, giving rise to the human immunodeficiency virus which causes AIDS in people.
Scientists have long believed that SIV causes little or no illness in the animals. But most of the previous research focused on monkeys, not chimps.
Now, however, an international research team studying chimpanzees at Gombe Stream National Park on the shores of Lake Tanganyika in Tanzania, has discovered that chimps do indeed succumb to the viral infection.
"Chimpanzees and humans are very similar genetically, so perhaps we should not be surprised that these closely related viruses cause disease in both hosts," said lead researcher Beatrice Hahn of the University of Alabama at Birmingham.
Infected chimps were 10 to 16 times more likely to die prematurely than uninfected chimps, according to the findings published in the journal Nature. Infected females had difficulty getting pregnant and their offspring often didn't survive. As in humans, the virus is transmitted sexually and through mother's milk.
Dr. Hahn said in a telephone interview that the discovery could broaden scientific understanding of the disease and may eventually lead to new treatments that benefit both humans and chimps.
"We believe the pathogen is not quite as bad [in chimps]as it is in humans," Dr. Hahn said. Chimps were likely infected with the virus long before it first jumped to humans about a century ago, giving the animals an extended period to adapt.