By Susan Milius
Getting used to people hanging around has been a mixed blessing for chimps in Africa’s Côte d’Ivoire.
Groups of chimpanzees in the Tai National Park have become habituated to people, allowing both researchers and ecotourists close access for decades. Respiratory diseases broke out among these chimps five times between 1999 and 2004, killing at least 15 animals. An international team now confirms the researchers’ fears: The pathogens probably came from people.
The samples available from seven chimps that died revealed either human respiratory syncytial virus or human metapneumovirus, says Fabian Leendertz, a wildlife epidemiologist at the Robert Koch Institute in Berlin. The viruses, common among people, infect the upper-respiratory tract and can open the way for fatal pneumonia. Adults typically suffer mild bouts, but in parts of the world with strained medical systems, the viruses account for considerable infant mortality.
Leendertz, the Tai project team, and colleagues compared the respiratory pathogens from the chimps with strains circulating among humans. The relationships nailed people as the disease source. “It’s a bit like Europeans bringing diseases to North America,” he says. The Tai researchers have started taking precautions such as wearing masks and touching as little as possible when out in the forest.
People aren’t all bad, say the researchers. They also analyzed poaching and found that signs of illicit hunting were less common closer to the research and tourist bases. So overall the human presence does benefit the chimps, the team reports in the Feb. 26 Current Biology.