At least 320,000 viruses remain undiscovered in mammalian hosts, a new study suggests.
A team of researchers from the Center for Infection and Immunity at Columbia University and EcoHealth Alliance collected biological samples from nearly 1,900 flying foxes in the jungles of Bangladesh. Scientists identified 55 viruses in nine viral families, of which only five were previously known. Their work was released in a study published in the journal mBio on Tuesday.
Researchers concluded there were at least three viruses unaccounted for in their samples, bringing the total number of viruses in flying foxes to 58. Their statistic extrapolation assumes that if each of the 5,486 known mammals carries 58 viruses, there are at least 320,000 viruses hosted by mammals.
"For decades, we've faced the threat of future pandemics without knowing how many viruses are lurking in the environment, in wildlife, waiting to emerge," said EcoHealth Alliance president and study co-author Peter Daszak in a statement.
"Finally we have a breakthrough – there aren't millions of unknown viruses, just a few hundred thousand, and given the technology we have it's possible that in my life time, we'll know the identity of every unknown virus on the planet," he said.
About 70 percent of viral diseases, such as HIV/AIDS, West Nile, Ebola, SARS and influenza originate in the wild.
"Historically, our whole approach to discovery has been altogether too random, said Center for Infection and Immunity researcher and lead author of the study Simon Anthony in a statement. "What we currently know about viruses is very much biased towards those that have already spilled over into humans or animals and emerged as diseases. But the pool of all viruses in wildlife, including many potential threats to humans, is actually much deeper."
Scientists say collecting evidence for these viruses could provide premeditative knowledge and treatment options in the event of an outbreak, but the operation would be costly, according to a Columbia press release. Roughly $6.3 billion would be needed to embark on such research, though limiting the research to 85 percent of viral diversity would bring the price tag down to $1.4 billion, the release said.