London, January 25 : The idea of involving local people in the vicinity of jungles to protect animals from poachers seems to have boomeranged, with an African study suggesting that the contact with humans may be making chimpanzees vulnerable to plagues.
Fabian Leendertz of the Robert Koch Institute in Berlin, Germany, who runs a chimp health project in the Tai forest in Ivory Coast, says that human gut bugs like Escherichia coli have been found in ape droppings.
Such bacteria are known to persist in the environment, where eco-tourists with diarrhoea deposit them.
Habituated Tai forest chimps had five separate outbreaks of respiratory disease between 1999 and 2005. Nearly all had cold symptoms, and between 3 and 19 per cent died, mainly juveniles.
Leendertz's team found either human respiratory syncytial virus or human metapneumovirus, and pathogenic bacteria like Streptococcus in victims.
"From the virus alone the chimps would have probably not have died," said Leendertz, adding that the bacterial infections that accompanied them were deadly.
The researchers, however, insist that disallowing researchers access to the areas inhabited by apes is not the right solution to the problem.
"In the Tai forest we have the highest density (of chimps) around the research and tourist sites. Without research our site would probably have (no chimps) left," New Scientist magazine quoted Leendertz as saying.
He says that researchers these days were heavy N95 hospital facemasks in the field.
"They're a bit hot, but OK. We need to find ways to maximise the benefit of research and tourism by minimising the negative effect of disease," he says.
Peter Walsh of the Max Planck Institute for Evolutionary Anthropology, a co-author on the study, said: "This is the first time people have quantified and compared the disease effects of research and tourism with the anti-poaching effect."
The study has been reported in the journal Current Biology.