One outbreak in Ivory Coast was sparked when an ethologist touched an infected, dead chimpanzee. In Gabon and the Republic of Congo, scientists linked several outbreaks to extensive deaths of forest chimpanzees and gorillas. And in this most current outbreak of Ebola in West Africa — which has been called “out of control” and has claimed at least 481 lives in Guinea, Sierra Leone and Liberia — is also believed to have begun in a remote location in the town of Gueckedou.
The commonality between numerous outbreaks of Ebola, scientists say, is growing human activity and deforestation in previously untouched forests, bringing humans into closer contact with rare disease strains viral enough to precipitate an epidemic.
“The increase in Ebola outbreaks since 1994 is frequently associated with drastic changes in forest ecosystems in tropical Africa,” wrote researchers in a 2012 study in the Onderstepoort Journal of Veterinary Research. “Extensive deforestation and human activities in the depth of the forests may have promoted direct or indirect contact between humans and a natural reservoir of the virus.”
Such a conclusion is particularly troublesome for West Africa, which has never before experienced an Ebola outbreak like this one, and is reported to have one of the world’s highest rates of regional deforestation. The Guinea Rainforest has been ravaged by deforestation and has shrunk to less than one-fifth of its original size. In Liberia, more than half of the forests have been sold off to logging companies, according to the Guardian. And Sierra Leone is “seriously threatened” by deforestation, according to Chatham House’s Illegal Logging Portal.
“There are no longer any frontier forests in West Africa for future generations to exploit,” researcher Jim Gockowski, who co-authored a study tracking Guinea’s deforestation, said in a statement.
What does that mean for Ebola? Quite a lot. For one, it may bring people and wildlife into closer contact than before. And it also means a lot more bats, thought to carry Ebola, may pervade some communities.
Some, however, contend the bats have always been a part of life in the southeast Guinea forests, and blaming bats isn’t accurate. One of those researchers is Melissa Leach, the director of the Institute of Development Science, who disagrees with what she calls the standard “outbreak narrative.”
“This assumes once extensive forests in which bats lived, separately from humans, have undergone progressive deforestation under the influence of population growth, land use, and climate change,” wrote Melissa Leach, the director of the Institute of Development Studies. “As bat habitats have fragmented and as people have moved into once-pristine forest areas, so human-bat contact has increased, making viral spillover more likely. While that sounds plausible, however, such a linear narrative is hard to apply convincingly to southeast Guinea.”
Indeed, other human activities may share equal blame. Researchers behind the article in the Onderstepoort Journal of Veterinary Research found deforested regions where locals hunted, dug for gold and farmed were most susceptible to an outbreak. The findings landed upon some dismal conclusions: The activities locals depend on the most are also what puts them at the most risk of contracting Ebola.
Mining, for one, “has become a big livelihood activity across the regions — Sierra Leone, Liberia, Guinea — as of the last couple of decades,” Melissa Leach told Mother Jones. That not only means mining deeper in the forests, but also “immense movement: people going seasonally in and out of mines, coming in and out, young people coming from all over the country.”
The burgeoning migratory behavior has also possibly played a role in the quick escalation of the current outbreak, which hopped from the forested villages of southeast Guinea to the western capital of Conakry. “There are lots of instances of human activities driving spillovers and outbreaks,” Jonathan Epstein, a veterinary epidemiologist and Ebola expert with EcoHealth Alliance, told Mother Jones. “While some of these things may be cultural traditions that have persisted for a long time, some of them are activities that are relatively newer, but intensifying.”
And as those activities intensify, so, it seems, do the outbreaks of Ebola.
*Correction: This article has been corrected to clarify the remarks of Dr. Melissa Leach, whose position was misrepresented. She does not think deforestation has driven more bats, some of which may carry Ebola, into southeast Guinea. Rather, she contends bats have long been a part of life in that region.