A population of fruit bats common across 2,800 miles of central Africa has been found to harbor the viruses, a joint study by the University of Cambridge and the Zoological Society of London found.
Thirty-four percent of African straw-colored fruit bats, which can live in groups of more than 1 million and often congregate near cities, were found to be infected with Lagos bat virus, a disease similar to rabies, while 42 per cent had been infected with henipaviruses, the researchers reported in the journal Nature Communications.
Fruit bats are often hunted for meat, which can result in a spread of these pathogens from animals to humans, the researchers said.
Henipaviruses have caused fatal disease in humans, pigs and horses in Southeast Asia and Australia, they said.
"In Australia ... the virus has spread into horses, and from horses, this virus has passed into vets tending sick horses, and this has killed a number of people in Australia," Cambridge epidemiologist James Wood told the BBC.
"In Malaysia there was a huge outbreak associated with pigs in 1999, in which more than 100 pig farmers and slaughter house workers died."
But was no evidence yet that either of the two viruses found in the bats had spread to humans in Africa, he said.
"I think that it's no immediate cause for panic -- these viruses have probably been there for a very long time in bats.
"But I think that it does raise questions relating public health surveillance and care that should be taken to avoid possible contact that might result in transmission," he said.