Scientists have found evidence of the deadly Ebola virus in a bat in Liberia, the first time the virus has been found in a bat in West Africa, researchers and officials announced Thursday .
A team of scientists working with the Liberian government presented their findings in Monrovia, the Liberian capital. The discovery represents a major step forward in understanding where Ebola cases come from, one of the largest unanswered questions surrounding these outbreaks, said Jonathan Epstein, a scientist with the EcoHealth Alliance, and a global nonprofit that is part of the research team
No human cases of Ebola are linked to this discovery, scientists said. Liberia has reported no new human cases since the end of the 2014-2016 epidemic that devastated West Africa, killing more than 11,000 people in Liberia, Guinea and Sierra Leone
Bats have long been suspected of being a natural reservoir or animal host for Ebola, meaning the virus can live and grow inside the animals without harming them. But more than 40 years ago and over two dozen outbreaks after Ebola emerged in Central Africa, researchers still do not know what animal or animals carry it, much less how it spreads to people
"It's been difficult to get definitive evidence , Epstein said.
The findings add to the evidence suggesting that bats could serve as the natural wildlife carrier for Ebola, scientists said. The team found genetic material from the virus and antibodies in the bat's blood, indicating the animal's immune response against infection
But Epstein and others warned that much more research is needed. Scientists tested samples taken from 150 Miniopterus inflatus bats in northeastern Liberia. But if only one of those bats has been tested positive, Epstein said.
If this species of bat, known as the long-fingered bat, turns out to be a natural host for the virus, scientists would expect to find more than one bat with antibodies against the virus, he said. It is also possible that the bat became infected by another bat species living in the same habitat, he said.
The Miniopterus inflatus bats live in caves, mines and forests, and eat insects. They are about the size of a small mouse, with about a 12-inch wing span.
"It's not un-useful "said Tom Ksiazek, a virologist at the University of Texas Medical Branch at Galveston, who specializes in hemorrhagic fever viruses such as Ebola.
" It's a step in the right direction , "Ksiazek said. "This suggests that certainly, the virus is naturally occurring in the ecology of West Africa."
Most experts say the natural animal host for Ebola is a type of fruit bat, not one that eats insects, he said. Previous evidence of Ebola in bats has all been in fruit bats, Ksiazek said. Rousettus aegyptiacus, has been found definitively to be the animal host of the Marburg virus, a close and equally fearsome cousin to Ebola
Scientists are writing a research paper about their discovery. But Liberian officials did not want to wait for publication, which may take a year, before releasing the information, Epstein said. Officials want to use the information to reinforce a public health message for Liberians to avoid bats to prevent potential infection. Bats can excrete the virus in their salivary, urine and feces. The animals are also a common food source;
The West Africa Ebola epidemic began with a single transmission from an animal to a 2-year-old boy in a remote village in Guinea, according to the World Health Organization. Scientists still do not know exactly how the child became infected, but researchers say it probably involved contact with wild animals. Before he became ill, he was seen playing near a hollow tree heavily infested with bats, according to a WHO report on the epidemic of 2015.
Scientists at Columbia University's Mailman School of Public Health, which is part of the team, are working to determine whether the virus found in the bat is the exact same virus that caused the West African epidemic and the current Ebola outbreak in Congo, which is the second-largest ever recorded.
These bats carry the deadly Marburg virus and scientists are tracking them to help stop its spreading