Viruses in Mammals: 320,000 Awaiting Discovery?

Annie Hauser Published: Sep 3, 2013, 1:03 PM EDT weather.com

A grey-headed flying fox. These bats are the largest flying mammal with a wingspan of up to 6 feet; they're also carriers of an estimated 58 viruses that could be transmitted to humans, according to a new study. (Wikimedia Commons/Mike Lehmann)

Close to 70 percent of emerging viral diseases — HIV/AIDS, West Nile, SARS, the newly discovered MERS virus — originated from animals. These diseases are zoonoses, or infections in the animal kingdom that have crossed into humans.
And these diseases are just the beginning of what's hiding in the animal kingdom. In fact, scientists estimate that there are a minimum of 320,000 more viruses lurking in mammals awaiting discovery, researchers from Columbia University's Mailman School of Public Health say in the journal Cell and Microbiology. Collecting evidence of these viruses, researchers said in a press release, could help detect and control disease outbreaks in humans.
Researchers estimate this proactive work would cost about $6.3 billion, just a fraction of the $16 to $40 billion 2003's global SARS pandemic cost economies around the world, according to a 2004 review.
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To make this estimate, researchers worked with the flying fox bat of Bangladesh (pictured above). After collecting almost 2,000 samples from wild bats, which were captured and released, the research team identified 55 viruses in the bats in a lab. Of these, only five were previously known.
Next, they estimated that there were another three viruses unaccounted for in the samples, upping the estimate of viruses in the flying fox to 58. Applying this finding to all 5,486 known mammals, researchers estimate there are at least 320,000 viruses among the mammals of the planet.
The relatively low cost of collecting and sequencing the bat samples means this technique could be applied across the animal kingdom — providing crucial preventive medicine for humans.
"To quote Benjamin Franklin, an ounce of prevention is worth a pound of cure," senior author W. Ian Lipkin, MD, director of the Center for Infection and Immunity (CII) at Columbia University's Mailman School of Public Health said in a press release. "Our goal is to provide the viral intelligence needed for the global public health community to anticipate and respond to the continuous challenge of emerging infectious diseases."
"If we know what's out there, we'll be a lot better prepared when a virus jumps over into a human population," lead author Simon Anthony, D.Phil added.