The first known Ebola outbreak occurred in 1976, and since then, scientists have been hunting for the origins of the disease. Like many maladies, Ebola is a zoonotic disease—its natural reservoir is an animal. Scientists have long suspected that fruit bats were playing that role for Ebola, but evidence that would definitively make that link never emerged.
Now, researchers think they are a small step closer to identifying Ebola's animal host. Rather than a fruit bat, scientists think the virus likely lives in a tiny insect-eating species called the Angolan free-tailed bat, National Geographic reports. While Angolan free-tailed bats were previously found to have antibodies for Ebola, scientists originally dismissed them as carriers of the virus because levels of those antibodies were quite low and because they didn't find evidence of the virus itself.
The new hypothesis is based on a bit of detective work in the village in Guinea that was home to the first victim of the 2014 Ebola epidemic—Emile Ouamouno, a toddler. Emile, National Geographic reports, died of Ebola-like symptoms last December, and his mother, grandmother and sister soon succumbed to the same disease. The fact that it was a child, not an adult, who first contracted the disease made researchers think that it wasn't a hunted animal that introduced Ebola to the village.
When the researchers began looking around the village, they found a large hollow tree near Emile's home where a colony of Angolan free-tailed bats lived. Villagers reported that kids played around the tree, the BBC writes, and Emile's friends attested to the fact that he liked to play there, too, and, as the New York Times adds, sometimes caught and played with bats living inside the tree. The scientists think that Emile likely was exposed to the virus either through the bats' droppings at the base of the tree or by directly handling the bats.
None of the bats the researchers captured around the village, however, turned up positive for Ebola, leading them to suspect that the virus must be rare in the wild, the BBC continues. This probably explains why Ebola outbreaks do not occur all of the time, considering the amount of bushmeat that is currently consumed in Ebola-endemic countries. The researchers plan to continue sampling the animals to see if they can identify a carrier.
Angolan free-tailed bats normally live deep in the forest, but they will also roost under roofs of village homes located in or near the woods, the BBC says. If they do turn out to be natural hosts for the virus, the knee-jerk reaction—to kill all the bats—would likely lead to other health repercussions for people living in the region. "Killing them would not be a solution. You would have more malaria," Fabian Leendertz, one of the studies' co-authors, told the BBC. "We need to find ways to live together with the wildlife."