Scientists estimate 320,000 new viruses
Indian flying fox
A new study suggests that there could be a minimum of 320,000 new viruses yet to be discovered in mammals.
Scientists from Columbia University say gathering information on these viruses could be critical to preparing for disease outbreaks in humans, and will cost less than a major pandemic such as SARS.
Although nearly 70 per cent of emerging virus diseases - such as West Nile, SARS and Ebola - are zoonotic - researchers say that until now there has been no strong estimate of the number of viruses in any wildlife species.
Co-author Peter Daszak said: "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."
A research team from Columbia University's Center for Infection and Immunity (CII) and EcoHealth Alliance collected 1,897 samples from flying foxes - the source of several outbreaks of Nipah virus - in the jungles of Bangladesh.
Using polymerase chain reaction, scientists were able to identify 55 viruses in nine viral families, of which 50 were newly discovered.
Five were already known viruses and three rare viruses were also detected, bringing the total estimate to 58. This number was then extrapolated to all 5,486 known mammals, coming to a total of 320,000 viruses.
Using the same method, researchers put the cost of surveillance, sampling and discovery of 85 per cent of all mammal viruses at £1.4 billion, compared with the economic impact of the SARS virus - calculated to be £16 billion.
However, researchers say the estimate is just a starting point and is likely to go up. The team will be continuing their work with two more studies, the first in a primate species in Bangladesh to compare their viral diversity to the flying fox's.
The second study will analyse six species of bat sharing the same habitat in Mexico to determine similarities in viruses. Researchers hope to extend their investigation to other viral families and species in the future.
The study, entitled "A strategy to estimate unknown viral diversity in mammals," has been published in the journal, mBIO.
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
