The scientists found 37 different viruses they believe have the potential to spread across the globe. All of them have shown the ability to spread between people, but have not so far caused a major epidemic. The Mers coronavirus, relatives of the Ebola virus, and several mosquito-borne viruses are singled out by the study. Researchers said these viruses had all caused disease outbreaks in the past and were the cause of "greatest concern". The method the team used to identify the most dangerous viruses has already predicted the threat of both the Ebola and Zika viruses before they emerged to cause major epidemics.