January 28, 2013
Link to African Ebola Found in Bats Suggests Virus Is More Widespread
For the first time, scientists have found evidence of the African Ebola virus in Asian fruit bats, suggesting that the virus is far more widespread around the world than had been previously known.
That does not mean that outbreaks of hemorrhagic fever are inevitable, said Kevin J. Olival, leader of the bat-hunting team at EcoHealth Alliance. But the possibility exists: bats are believed to drink out of jars attached to trees to collect tasty date palm sap, and fatal outbreaks in Bangladesh of Nipah virus, which is not related to Ebola, have been blamed on fresh sap contaminated with bat saliva, urine or feces.
Palm sap gatherers should be encouraged to put bamboo covers on their collecting jars to keep bats out, Dr. Olival said.
For the study http://wwwnc.cdc.gov/eid/article/19/2/12-0524_article.htm#r4 , published this month in Emerging Infectious Diseases, his team caught 276 bats in four Bangladesh districts.
“These bats roost in caves, but there are very few caves in Bangladesh, so we put up mist nets outside old ruins that looked like something out of ‘Indiana Jones,’ ” he said. “In the evenings, they would come out to forage.” The team would untangle the bats, draw blood and take saliva, urine and fecal samples, and release them.
Five of them — all from the Rousettus leschenaultia species — reacted to tests for antibodies http://health.nytimes.com/health/guides/test/antibody-titer/overview.html?inline=nyt-classifier to Zaire Ebola virus. The researchers did not find any virus itself, so it was not possible to do genetic sequencing and see exactly how close the match to the African strain was.
Although closely related species of fruit bats are found in Africa, India and China, their territories do not overlap and these bats don’t migrate long distances, Dr. Olival said, so it was likely the virus had been in a bat ancestor species for millenniums. A related virus, Ebola Reston, which is not known to sicken humans, has been found in Philippines fruit bats, and an “Ebola-like” virus has been found in insect-eating bats in Spain. But the match in Bangladesh was closest to Zaire Ebola.
Ebola was at first thought to be a gorilla virus, because human outbreaks began after people ate the bodies of dead gorillas. But scientists believe that bats are the natural reservoir and that primates may get infected by eating fruit that bats have drooled or defecated on.