Link between deforestation and ebola a lesson in habitat encroachment
Ebola outbreak hotspots match deforestation patterns, a Kiwi expert in disease patterns has found.
World Health Organisation estimates more than 11,000 people died in West African countries during the 2014 outbreak of a new strain of the grisly disease that causes internal and external bleeding.
Massey University epidemiologist Dr David Hayman began investigating the virus in Africa before the new strain began infecting humans, when he came across ebola in gorillas, chimpanzees and bats.
His latest work helps trace how it spreads between humans and fruit bats, believed to be the source of outbreaks. The findings provide clues to places and times ebola could occur in the future, and how consumer demand could contribute.
"[The 2014 strain of] ebola in humans appeared to come out of nowhere, but we'd been thinking about this because we'd found antibody evidence of this virus in bats in fragmented forest around cities, but not in urban-dwelling fruit bats," he said.
With an international team, he analysed data showing where the outbreak was concentrated, compared with satellite images of forest density.
"We wondered if it was just because people were there, but we tested [and] it was actually due to the fragmented forest with people present... as people start to encroach."
Fruit bat populations increase in fragmented forest conditions, while their contact with humans also increases.
Deforestation is increasing in West Africa to provide land to grow cocoa and palm oil and in central Africa, where other ebola outbreaks have occurred, to meet demand for hardwoods.
"It shows there's different implications in how you encroach in the environment. We in very rich countries, what are we doing that's encouraging deforestation and habitat encroachment?
"It's very easy when something like this happens in countries in West Africa to assume that it's all their fault."
Future ebola outbreaks are an increasing risk, as deforestation and fruit bat populations continue to increase, he said, but conservation efforts and education about safe contact with animals could help.