It seems chiroptophobes may have been right all along.
A new article by Nature reveals how scientists who analyzed a broad range of mammalian host-virus relationships discovered that "bats harbour a significantly higher proportion of zoonotic viruses than all other mammalian orders." That means the potential for a bat-borne viruses to cross over and infect humans is higher than for other animals.
Many of the biggest pandemics in human history were zoonotic -- meaning, resulting from infectious diseases crossing over from animals to humans. The Black Death, which killed tens of millions in the 14th century, was zoonotic -- a result of the bacterium Yersinia pestis that was transmitted to humans via fleas that lived on rats. Moreover, HIV is now widely considered to have crossed over to humans from apes, who harbor a similar virus called Simian immunodeficiency virus (SIV).
Rather than base their predictions purely on the number of zoonotic viruses a given animal species harbored, the new study specifically weighed risk based on their likelihood of human contact and genetic similarity. "We hypothesize that the number of viruses a given mammal species shares with humans increases with phylogenetic proximity [genetic similarity] to humans and with opportunity for human contact," the joint authors wrote.
There are some caveats to the authors' conclusions, though. The authors note that their estimates of viruses are based on observation. They note specifically that their study could not account "for viruses or host associations that have completely evaded human detection to date, nor those identified but not published."
That said, the authors believe that their study will "allow us to identify which species and regions should be preferentially targeted to characterize the global mammalian virome,"and thus protect humanity from potential future outbreaks.