Published on January 30, 2020 Written by Admin Bat Conservation International’s FAQ on Bats, Coronaviruses, and Zoonotic Disease
Bat Conservation International is monitoring the news and information about the spreading novel coronavirus (nCoV-2019) that was first detected in Wuhan, China. As bats have become intertwined in the coverage, we are providing this FAQ to help our community and members interpret and navigate the evolving information and understand why bats are mentioned. What caused the nCoV-2019 outbreak? A live wildlife market (sometimes called a ‘wet’ market) in Wuhan, China is believed to be the source of the current nCoV-2019 outbreak. Live wildlife markets are places where live animals, including wildlife harvested both illegally and legally, are stacked closely together in cages and slaughtered and sold for food.
Wildlife species sold at live markets are diverse – including bats, civets, bamboo rats, snakes, birds, and many other species, alongside domestic animals such as chickens, pigs, dogs, etc. The conditions of these wet markets with live animals stacked closely together in stressful and unsanitary conditions increases the chance that viruses can ‘spillover’ from one animal host to another and to humans. (see What is a Zoonotic Disease? below). Currently, we do not know exactly how the nCoV-2019 pathogen jumped from animal to human. Specifically, we do not know whether the viral spillover to humans involved direct contact with a bat or another wild animal sold at live wildlife markets in China. There is also a possibility that viral spillover happened via animal contact outside of the Wuhan market, and was brought into the market by infected people. Why are bats mentioned in the news about Wuhan Coronavirus? Research released on January 23rd, 2020 on bioRxiv.org by Chinese researchers at Wuhan Institute of Virology shows that that nCoV-2019 shares 96% of its genome with SARS-like coronaviruses. Bats, specifically Rhinolophid (Horseshoe) bats in China, are the natural wildlife reservoirs for SARS-like coronaviruses. It is likely that bats are the natural wildlife reservoir of nCoV-2019, even though another “intermediate” species could have been involved with direct transmission to people. Bats carrying coronaviruses in the wild undisturbed by people are not a threat to human health. The NY Times published this opinion piece explaining why bats carry so many viruses and why more research is so important. What is a zoonotic disease and what is a spillover event? A zoonotic disease is a disease that spreads from an animal population to humans. A pathogen (for example a specific type of virus or bacteria) may occur naturally in a ‘reservoir’ animal population with little to no ill effect on the animals carrying it. A spillover event occurs when the pathogen is transmitted to a novel host, such as another animal species or directly to humans. Pathogen spillover into novel hosts can sometimes cause a disease outbreak in the new host, and could also lead to rapid mutation or increased virulence. These spillover events usually require close contact with bodily fluids of animals in unsanitary conditions. How are conservation and global health vitally linked? Live animal markets and trafficking in wild animals is at the heart of this global health threat. The Wildlife Conservation Society issued a position statement calling for the closure of all live markets in China. There is a temporary ban on live markets in China, but without a permanent closure, the risk remains for future spillover events. As David Quammen entitled in his New York Times opinion piece on January 28th: “We made the Coronavirus Epidemic”. Specifically, we made it by engaging in unsustainable ecological destruction and the dangerous and devastating trafficking and illegal trade of wildlife for human consumption. Dr. Kevin Olival at EcoHealth Alliance points to closing and cleaning up wildlife markets as a win-win solution in an article in National Geographic: “One intervention, which is fairly simple, is reducing the wildlife trade and cleaning up the wildlife markets. Cutting back the wildlife trade has a win-win effect of both protecting species that are harvested from the wild and of reducing spillover of new viruses.” How is bat research important for human health? Studying zoonotic disease, including identifying wildlife reservoirs for pathogens, increases our understanding and ability to predict and prevent zoonotic spillover events. The virology, immunology, and ecology of bats is of crucial importance to developing strategies to inform conservation and global human health outcomes. Furthermore, studying bat immunology can help us understand our own immune systems and ways to fight diseases. What is One Health? The One Health approach recognizes that public health is inextricably linked to healthy environments. “One Health is defined as a collaborative, multisectoral, and transdisciplinary approach — working at the local, regional, national, and global levels — with the goal of achieving optimal health outcomes recognizing the interconnection between people, animals, plants, and their shared environment.” – CDC website