Merlin Tuttle’s Comments on Misleading Story about Bats & Disease
I was quite surprised to find Dana Kobilinsky’s story, Bats Spread Viruses Across Species, posted by The Wildlife Society on September 9. This story runs in stark contrast to your organization’s longstanding dedication to scientific understanding and conservation of wildlife, including bats.
Still unproven supposition is presented as fact, and it is assumed without supporting evidence that spreading viruses across species is always bad.
Bats in fact have one of our planet’s finest records of living safely with humans. Despite intense efforts to link Ebola to bats, “No clear case of bat-to-human transmission of Ebola has ever been proven.” (G. Vogal, Science, 2014, vol. 344:140). Nevertheless public health virologists have so frequently speculated that this and other so-called “emerging diseases” are of bat origin, that unproven hypotheses are becoming entrenched as “fact” in the public mind.
Throughout most of human history bats and people have shared dwellings, from caves to thatched huts. Only recently have we begun living mostly in modern buildings which exclude bats. With such long association, one might logically expect bats and people to have co-evolved unusual resistance to each other’s pathogens, a possibility that hasn’t been investigated.
Those attempting to scare us can’t explain how millions of people still hunt and eat bats every year without documented harm or how colonies of hundreds of thousands of bats that live in cities from Africa to America continue to have an impeccable safety record. It is even more difficult to explain how hundreds of bat researchers like me have survived close, career-long association with bats on every continent where they occur, often surrounded by millions at a time in caves, without a single one of us contracting one of these so-called “emerging diseases.” Like veterinarians, we are vaccinated against rabies to protect against defensive bites from animals we handle, but that has been our only protection.
Put in perspective, mortality from our much beloved dogs dwarfs any associated with bats (http://www.who.int/mediacentre/factsheets/fs373/en/). However most of us have had sufficient experience to understand that we are unlikely to be harmed by a dog, and we’d be irate if anyone distorted the facts about dogs as is done for bats.
As documented in Juan Enriquez and Steve Gullans’ new book, Evolving Ourselves (Penguin Group/Random House, 2015), our current understanding of viruses is miniscule. More than 99 percent of viruses remain undiscovered by scientists, and despite our inordinate fears, most are likely benign or even essential to our very survival. Failure to understand the beneficial ones may one day be our undoing. Yet as Enriquez and Gullans point out, “it is hard to get grants to study the nice viruses.” It is far easier to scare us into funding studies of the bad ones, and given the already widespread superstitious fear of bats and the unknown it isn’t surprising that those who profit from our fears love to pick on bat/virus combinations!
When even a few new viruses are discovered in bats they are typically announced as though bats are therefore uniquely dangerous. Lots of new viruses can be found wherever we look. Enriquez and Gullans cite a 2013 study in which 478 relatively abundant viruses were discovered in a single human being, most of them new to science.
It is easy to become prematurely frightened when we are told that a newly discovered virus from a bat is related to deadly ones like SARS and Ebola. However, given the infancy of our knowledge of virus taxonomy, such claims can be highly misleading. All life is related to some extent. We don’t confuse ourselves with chimpanzees just because our genomes are 96 percent identical. And we don’t even know that viral relationships are always bad. Some may even help convey resistance to those we fear.
Most viruses are likely benign, and many may be essential to our very survival. Unfortunately it is far easier to obtain grants hypothesizing already feared and misunderstood animals like bats as potentially dangerous harbingers of rare, but scary viruses like SARS and Ebola. And these are made even more sinister by referring to them as “emerging pathogens,” though available evidence suggests they’ve been here for a very long time, simply unnoticed due to being rare and limited to remote areas.
Recent speculation by public health virologists has netted millions of dollars in grants to search for deadly viruses in bats, and given that viruses are exceedingly abundant in all living creatures, they’ve been easy to find. However, the same premature speculation that sells media readership and gains big research grants today, may also damage the credibility of a whole generation of much needed public health virologists. Diverted funds are urgently needed to fight far more serious, largely preventable killers like cancer (http://www.who.int/mediacentre/factsheets/fs297/en/) and childhood obesity (http://www.who.int/features/factfiles/obesity/en/).
For me, well documented experience trumps speculation. It’s time for the Wildlife Society, as a much admired, science-based guardian of wildlife, to take a stand in defense of far too carelessly maligned bats, and I would be happy to help.
I do recognize that Kobilinsky warns that bats are valuable and shouldn’t be killed. However, as one who has engaged in extensive world travel on behalf of bats for more than 55 years, I have repeatedly met people who have exterminated large bat colonies due to unfounded fear of disease. And no group of mammals is more uniformly beneficial nor persecuted and endangered than the flying foxes, represented in Kobilinsky’s story by an exceptionally sinister photo, which itself will counter a thousand words.