Ebola Species Found in Bats ahead of Any Potential Outbreak. USAID Global Health, August 28, 2018.
For the first time, a discovery by the PREDICT project uncovered a new Ebola virus in animals before it spread to humans.
The discovery of the Bombali virus in bats in Sierra Leone and the sequencing of the complete genome was published yesterday in the journal Nature Microbiology. The government of Sierra Leone announced preliminary findings in late July.
The discovery was made by scientists at the University of California Davis’ One Health Institute and Columbia University’s Center for Infection and Immunity, working with the government of Sierra Leone and the University of Makeni and Metabiota. The work is part of the PREDICT Ebola Host project, funded by USAID.
PREDICT in Action
The discovery illustrates the mission of PREDICT, which aims to find viruses before they reach humans. The Bombali virus has the potential to infect human cells, but it is unknown if the virus has already caused human infection or is harmful to humans.
“Identifying new viruses like Bombali in wildlife and testing their capacity for human infection can enhance our understanding of the pre-emergent viral diversity circulating in animals,” said co-lead author Simon Anthony, a virologist at Columbia University’s Mailman School of Public Health. “We want to discover viruses that have the genetic prerequisites for human infection and then prioritize them for further study and intervention.”
Bats Likely Hosts of Ebola Viruses
Prior to the discovery of Bombali, five Ebola virus species had been characterized in previous publications. For instance, Bombali Ebola is different from the Zaire Ebola virus, which killed thousands of people between 2013 and 2016. Despite more than 40 years of research, the reservoir hosts for these viruses is still unknown. However, the discovery of Bombali adds to growing evidence that bats are the likely hosts of these viruses.
“If you want to prevent Ebola outbreaks, it’s important to know which species are hosts and can shed the virus,” said co-lead author Tracey Goldstein, an associate director of the One Health Institute at the UC Davis School of Veterinary Medicine. “Then we can help target changes in behavior so we can protect people, which is the overarching goal of our work.”
The PREDICT team sampled more than 6,000 animals in Sierra Leone and performed laboratory tests to look for both known and unknown Ebola viruses. Bombali was found in five individual bats belonging to two different species of insectivorous bats that were found roosting in people’s houses.
Don’t Kill Bats
The researchers emphasize that people should not attempt to kill or eradicate bats in response to the discovery. In fact, killing bats can actually increase the risk of virus transmission. When under constant stress from human attacks, healthy bats become weaker and more susceptible to catching the virus from infected bats, and can then spread Ebola to other geographic areas.
Bats also play important ecological and agricultural roles for pollination. Insectivorous bats eat thousands of insects every night, helping to control pests that can transmit disease and damage crops.
Researchers have been working with local communities throughout the project. They continue to share results, answer questions and discuss with communities how they can live safely with bats by reducing their risk of exposure to the virus.
Infected bats are not known to show signs of illness but can shed the virus in their saliva and feces. As a result, other animals and people may be exposed if they touch live or dead bats, ingest food or water in which bats have fed, or come into contact with the urine or feces of infected bats.