Epidemiologists Acknowledge Virus Hunting as a Costly Waste

By Merlin Tuttle

Leading epidemiologists are finally acknowledging that the recently huge expenditures for virus hunting (mostly focused on bats) have little practical value in disease prevention. The June 7 issue of Nature contains a key paper titled, “Pandemics: spend on surveillance, not prediction.” In it Edward Holmes, Andrew Rambaut, and Kristian Anderson combine their expertise to advocate a much-needed change of course in prevention of viral transmission from animals to humans, one that may also considerably brighten the future of bats.

They emphasize that broad surveys of animal viruses have little practical value when it comes to disease prevention and warn that “Trust is undermined when scientists make overblown promises about disease prevention.” They “urge those working on infectious disease to focus funds and efforts on a much simpler and cost-effective way to mitigate outbreaks—proactive, real-time surveillance of human populations.”

Bats have an exceptional record of living safely with humans. But, they have been disproportionately searched, and victimized by virus hunter speculation, apparently because they are unpopular and easy to sample. This is an Angolan free-tailed bat (Mops condylurus), a species targeted for eradication following premature speculation linking it to the 2014 Ebola outbreak.

These experts explain that predicting when and where a virus will emerge in people is misguided and unlikely to be achievable. Determining which of an estimated 1.6 million animal viruses, deemed to be potentially capable of transmission to humans, would also prove prohibitively costly. They conclude that “given the rarity of outbreaks and the complexity of host-pathogen interactions, it is arrogant to imagine that we could use such surveys to predict and mitigate the emergence of disease.”

Currently, the most effective way to fight outbreaks is to monitor human populations in the countries and locations that are most vulnerable. Recommended actions include detailed screening and isolation of people exhibiting difficult-to-diagnose symptoms and monitoring of animal die-offs.

This is not the first warning against recent investment of billions of dollars on viral witch hunts that unfortunately have focused primarily on bats. Nevertheless, it appears to be the first to be taken seriously by a major journal of science.

On June 17, 2017, Nature published a paper, “Bats are global reservoir for deadly coronaviruses,” which claimed that finding these viruses could help predict where they are likely to make the next jump from animals to humans. After supporting virus hunting in bats, at the very end, it briefly admitted that Michael Osterholm, a prominent epidemiologist, believes that researchers and politicians should, instead direct their limited resources to halting outbreaks of already known-to-be deadly viruses.

A similar article titled, “Can Virus Hunters Stop the Next Pandemic Before It Happens?” was published on January 25, 2018 by the Smithsonian. Though this article asks the right question, it too mostly promotes the virus hunting approach. Only at the very end, does it acknowledge Robert Tesh, also a leading expert on zoonotic viruses, as having an opposing view.

Referring to the so-called virus hunters, he expressed his opinion that “A lot of the stuff they produce is hype. It’s more PR than science.” Tesh refers to Zika and West Nile viruses, noting that neither is new. They were transported to new areas, then spilled over, events that he doubts could have been predicted. He also notes that many reassortment viruses mutate quickly and that no amount of discovery could prepare for that. Tesh concludes that “Given these variables and how little we really understand them, people who claim they can predict what will happen are fooling themselves and the funding agency.”

Though Osterland, Tesh and others have previously expressed doubts about virus hunter claims, the current paper in Nature is the first to treat such concerns with appropriate respect. I’m delighted to see such progress in countering a now almost universal misperception that, has not only led to huge misallocation of public health funding, but also threatens the future of inappropriately maligned bats.



Holmes, E.C., A. Rambout, and K.G. Andersen. 2018. Pandemics: spend on surveillance, not prediction. Nature, 558:180-182.

Maxmen, A. 2017. Bats are global reservoir for deadly coronaviruses. Nature, 546:340.

Morrison, J. 2018. Can virus hunters stop the next pandemic before it happens? SmithsonMag.com. https://www.smithsonianmag.com/science-nature/how-to-stop-next-animal-borne-pandemic-180967908/.

Tuttle, M.D. 2017. Give bats a break. Issues in Science and Technology 33, (Spring 2017):41-50.

Tuttle, M.D. 2018. Fear of bats and its consequences. J. Bat Research and Conservation, 10(1).  https://doi.org/10.14709/ BarbJ.10.1.2017.09.