In the past week, my social media feeds – which encompass many people who love bats and support conservation – have been increasingly full of pleas and demands for the media to stop villainizing bats for the 2019-nCov outbreak. I can understand this sentiment; I certainly do not want mobs of people with torches and pitchforks to go out and cull bat colonies to try to protect human health. In fact, even in cases where the transmission of a deadly virus to people is ongoing, like transmission of rabies from vampire bats to people in Peru, killing a bunch of bats doesn’t necessarily reduce human risk; it might even increase it, due to complex disease dynamics! So the sentiment to be careful with how we portray the threats that bat-borne viruses pose for public health in news articles is one that I can support.
HOWEVER, today these social media posts contain a new element: a blog post by a famous bat conservation biologist, Merlin Tuttle, who argues that we have no reason to implicate bats in the 2019-nCov outbreak, and that researchers who are trying to find this virus and other viruses in bats are just in it for the easy research and grant money, because virus spillover from bats to people is very rare and not worth studying:
“…Compared to snakes or other animals, they [bats] are by far the easiest to quickly capture and process, have few defenders, and are already widely feared. Associating bats with rare, little-known viruses provides tempting opportunities for quick publication, big grants, and career advancement14.
Nevertheless, history does not support this bias. The great pandemics have come from birds, rodents or primates, not bats15. In truth, bats have one of our planet’s finest records of living safely with humans2,14.”
If you have been a long-term follower of this blog, you’ll know that I have never once criticized a paper or focused on the negatives, because I generally find that to be unproductive. But this is not Merlin’s first wildly irresponsible post that pits the general public against researchers by misrepresenting the scientific literature, and I fear that this one could have real negative impacts. So in this space, I want to provide some resources to people interested in bat conservation to learn more about how viral spillover events (like this coronavirus epidemic) and bat conservation are related.
Let’s start with some general information about spillover of viruses from bats. There is no question that bats are reservoirs for many viruses that cause serious human illnesses. These include viruses like SARS, rabies, and some paramyxoviruses like the Hendra and Nipah viruses. Because these viruses are such a big deal, there has been a lot of recent attention to bats and their potential as reservoirs for high-impact emerging zoonotic viruses. This work has shown that bat species do seem to be reservoirs for a disproportionate number of viruses, on average, in comparison to species in other taxonomic groups, like rodents. And there might be several reasons why bats have so many viruses but can live with them without being sick. Bats are reservoirs for many coronaviruses and similar viruses (e.g., SARS), so it is highly like that the 2019-nCov has a bat reservoir.
Bats can infect people with these viruses in many different ways. For instance, people can become infected by the rabies virus when they are bitten by a bat or when they contact bodily fluids from bats. People could also become infected by batborne viruses by handling bats or consuming bats, or by consuming things that bats defecated on/in (as in the palm sap and Nipah example). And finally, bats can infect other wildlife or domesticated species, and people can become infected by contacting/consuming those other species. We do not know which transmission route led to spillover from bats to people for this coronavirus, but in general, wildlife markets (for consumption or pet trade) do bring together bats, other wildlife, and people in unnatural ways, and there is a lot of potential for spillover from bats to people in these settings.
Viral spillover from bats is a real threat to global human health and has serious impacts on global economies, so we should be doing everything we can to neutralize those threats. One of the best ways to do that is by advancing global bat conservation. In particular, if we can keep bats in their undisturbed, natural habitats, we can minimize the chances of bat to human transmission. This isn’t as easy as saying, “Stop eating bats!” The global community needs to make a real effort to ensure that in places with high bat diversity (and thus high bat virus diversity), people are empowered to conserve bat habitats and bats because they have enough to eat, don’t need to cut down forests for fuel, etc.
If you have helpful resources for learning more about spillover of viruses from bats and how to use these spillover events as opportunities to advance local and global support for bat conservation, please leave them in the comments!