SHOCKING: First estimate of total viruses in mammals

Minimum of 320,000 viruses; identifying them could help mitigate disease outbreaks; total cost less than a single pandemic
Scientists estimate that there is a minimum of 320,000 viruses in mammals awaiting discovery. Collecting evidence of these viruses, or even a majority of them, they say, could provide information critical to early detection and mitigation of disease outbreaks in humans. This undertaking would cost approximately $6.3 billion, or $1.4 billion if limited to 85% of total viral diversity -- a fraction of the economic impact of a major pandemic like SARS.

Close to 70% of emerging viral diseases such as HIV/AIDS, West Nile, Ebola, SARS, and influenza, are zoonoses -- infections of animals that cross into humans. Yet until now, there has been no good estimate of the actual number of viruses that exist in any wildlife species.

"Historically, our whole approach to discovery has been altogether too random," says lead author Simon Anthony, D.Phil, a scientist at the Center for Infection and Immunity (CII) at Columbia University's Mailman School of Public Health. "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. A more systematic, multidisciplinary, and One Health framework is needed if we are to understand what drives and controls viral diversity and following that, what causes viruses to emerge as disease-causing pathogens."

"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. Finally we have a breakthrough -- there aren't millions of unknown virus, just a few hundred thousand, and given the technology we have it's possible that in my lifetime, we'll know the identity of every unknown virus on the planet," adds Peter Daszak, PhD, corresponding author and president of EcoHealth Alliance.