Following years of headline speculation reporting bats to be the reservoir for Ebola, a review of current knowledge points elsewhere. This often fatal disease is caused by the Ebolavirus genus, which includes five species (Sudan, Zaire, Bundibugyo, Tai Forest and Reston virus). The geographical distribution of these species along separate river basins is inconsistent with a highly mobile source, such as bats, that easily cross basin borders.
Furthermore, repeated attempts to isolate infectious Ebola viruses from bats have failed. Experimentally infected bats have shown no evidence of viral shedding, and repeated efforts to isolate these viruses from a wide variety of fruit- and insect-eating bats caught at outbreak locations have failed.
Available evidence suggests a possible link to aquatic or semi-aquatic animals. “Many ecological aspects of rivers that might be important key events for viral emergence have not been considered.” Aquatic insects have not been sampled. However, even such seemingly unlikely ones as mayflies could provide a source for ecological transmission when inadvertently consumed by grazing animals. If this were the case, then a decline of insect predators, that may be resistant to infection, could contribute to Ebola outbreaks.
Ironically, in such a scenario the killing of insectivorous bats, which are major predators of aquatic insects, could increase the risk of outbreaks.
This review also raises the possibility that even Marburg virus may be originating from a source other than bats. For the full publication go to http://www.mdpi.com/1999-4915/8/2/30
