Ebola: bats get a bad rap when it comes to spreading diseases

One of the greatest global health threats lies in emerging diseases, which have never been seen before in humans or — as with Ebola — appear sporadically in new locations. Most emerging diseases are zoonoses, meaning they are caused by pathogens that can jump from animals into people. Out of more than 300 emerging infections identified since 1940, over 60% are zoonotic, and of these, 72% originate in wildlife. Whereas some zoonotic infections, such as rabies, cannot be transmitted between human patients, others can spread across populations and borders: in 2003, SARS, a coronavirus linked to bats, spread to several continents within a few weeks before it was eliminated, while HIV has become, over several decades, a persistent pandemic. The unpredictable nature and novelty of zoonotic pathogens make them incredibly difficult to defend against and respond to. But that does not mean we are helpless in the face of emerging ones. Because we know that the majority of zoonoses pass from wildlife, we can start to identify high-risk points for transmission by determining which wildlife species may pose the greatest risk.