FAQs COVID-19 and Bats
The current COVID-19 pandemic has been unprecedented with major impacts on people’s health and livelihoods across the globe.
This document answers some Frequently Asked Questions about COVID-19 and bats. It’s important to remember that COVID-19 is a human disease, not a bat disease. As far as we currently know, the pandemic started with just one spillover of SARS-CoV-2 (the virus that causes the disease COVID-19) from an unknown animal host to humans. After that first transmission, all other cases came from the virus spreading from human to human.
A short, animated video (https://www.youtube.com/watch?v=gilj-fd77Ew) by the Spanish Association for the Conservation and Research of Bats (SECEMU), with input from the UK’s Bat Conservation Trust, explains why we should not blame bats for COVID-19.
Why are we supplying an FAQ?
There is a lot of misinformation circulating around the COVID-19 pandemic. It is really important that everyone checks the facts behind the stories you read or post on social media platforms. There are excellent fact checking websites, including Full Fact UK, Snopes, the FAIR website and the Misinformation Watch and Coronavirus website, to help separate accurate information from misinformation.
These FAQs are based on guidance from the Bat Conservation Trust.
If you are a researcher, bat rehabilitator or caver please see the Bat Specialist Group website for more detailed guidance.
What is the difference between a virus and a disease?
A virus is a type of infectious agent, or pathogen, that may cause disease in the host it infects. In other words, the disease is the illness caused by infection with the virus. COVID-19 is the disease caused by the virus SARS-CoV-2.
What is a spillover?
A spillover is when a pathogen jumps to a new host, such as another animal species or humans. When pathogens spill over, they can sometimes cause a disease outbreak in the new host. SARS-CoV-2, the virus that causes COVID-19 in humans, is likely to have spilled over from another animal just once with all subsequent transmission between humans; it is not continually spilling over from animals to humans.
Do bats carry more viruses than other animals?
Bats are a highly diverse group of animals (over 1400 species) and because there are so many different species of bats, they host a lot of different viruses (1). Taking this into account, bats are not exceptional in terms of the number of human disease-causing viruses they host when compared with other groups of mammals or birds. Most viruses carried by bats are not pathogenic to humans and the number that are is proportional to the number of bat species (1). It is also important to note that while bats host some pathogens that can infect humans, they are victims of disease outbreaks too.
What is a coronavirus?
Coronaviruses are a large and diverse family of viruses found in many different wild and domestic birds and mammals. Four coronavirus species can cause the common cold in humans, while three cause serious respiratory illness (SARS-CoV, MERS-CoV, and SARS-CoV-2, the virus causing COVID-19 (2)).
Where does SARS-CoV-2 come from?
The short answer is that we don’t know for certain yet. Scientists do agree that COVID-19 is caused by a coronavirus called SARS-CoV-2 (3,4). COVID-19 is a zoonosis, which means it is a human disease that came from animals. However, we still do not know the animal host of SARS-CoV-2 or how it got to humans. As far as we currently understand, the pandemic started with just one spillover of SARS-CoV-2 from an unknown animal host to a human. After that first transmission, all other cases came from the virus spreading from human to human (5). This means that transmission from human to human, not animal to human, is what led the disease to spread globally. The closest known relative to SARS-CoV-2 is another coronavirus found in one species of bat (Rhinolophus affinis), but this bat coronavirus has never been found in a human (4) and SARS-CoV-2 itself has never been found in bats.
Can I get COVID-19 from bats?
No, the virus that causes COVID-19 has not been isolated from any of the world’s 1420 species of bat (though only a small number of species have been tested to date). A coronavirus that is 96% similar to SARS-CoV-2 has been found in a single species of bat, Rhinolophus affinis, in China (4). This may sound very similar, but to put it in context, we share 95% of our genome with chimpanzees but we are not the same species.
How did COVID-19 get from wildlife to people?
COVID-19 is a human disease, not an animal disease. However, the ancestor of SARS-CoV-2 came from animals. The transmission of any infectious disease pathogen from an animal to a human is a complex process. In the case of COVID-19, SARS-CoV-2 diverged from an ancestor virus 40 - 70 years ago, most likely from a bat in the genus Rhinolophus (4,6). However, we do not yet know the pathway that led this ancestral bat virus to become the SARS-CoV-2 virus that infected humans. Based on what we know about other coronaviruses, it is likely that the ancestor of SARS-CoV-2 was first transmitted from bats to another animal with a higher chance of infecting humans. For example, it’s currently recognized that spillover of the viruses causing SARS and MERS in humans each involved an intermediate host that brought those viruses into contact with humans (7). However, transmission of SARS-CoV-2 from human to human, not animal to human, is what led the disease to spread globally.
In general, for zoonotic spillover to occur, pathogens must overcome a series of barriers that would otherwise prevent human infection. Factors include the health of the animal host, how and when the pathogen leaves the animal’s body, how long it remains in the environment, how humans come in contact with it and how the human immune system is able to respond (8). Changes in any of these factors (e.g. the host animal’s health deteriorates or humans come into contact with the pathogen more often than usual) may lead to an increased risk of human infection.
Human changes to the environment can increase the risk of spillover by bringing wildlife into closer proximity to humans and domesticated animals such as livestock, regardless of the animal source of the virus. In the past, some pathogens have jumped from animals to humans through their interactions, perhaps via land use or ecosystem change, hunting and consumption of game, and travel (9). The wildlife trade provides additional opportunities for spillover (9). However, spillovers are sporadic events and are often associated with one or a few human cases that mostly remain undetected and do not lead to a larger epidemic or pandemic. To cause an outbreak such as COVID-19, a pathogen must take further critical steps, especially becoming able to transmit from person to person.
Would killing bats stop the disease?
No, killing bats will not end the COVID-19 pandemic nor decrease the risk of future disease outbreaks because the virus is being transmitted from human to human. In addition, culling wildlife can actually increase the risk of disease transmission, since this event could disperse and stress animals causing them to shed more viruses, and over a larger area.
In Uganda, Egyptian rousette bats were killed in a mine after it was found they were carrying Marburg virus. Those actions ignored advice from US and Ugandan authorities. Four years later, there was another outbreak of Marburg nearby, and it was found that a new population of bats had moved into the mine with higher infection rates than before. The reactionary killing of bats had increased the disease risk (10).
Can we live with bats safely?
Yes, and we already do. Bats live on six continents and form a vital part of the world’s ecosystems, as well as providing enormous benefits to humans through pollination, seed dispersal and pest control; services that are worth billions of dollars annually to the world’s economy. Bats live alongside us in both urban and rural environments, in our gardens, parks and even roosting around our homes, without posing a threat (11).
Many bat species are in trouble and need our help to survive. In some countries they have legal protection, but globally many don’t. Much more needs to be done to ensure the survival of bats and other wildlife around the world. While the killing of bats will not reduce spread of COVID-19, it would adversely affect the conservation of bat populations and the benefits they bring to humans and ecosystems.
Can I give COVID-19 to a bat?
We don’t yet know whether humans can pass the virus to bats. If you are lucky enough to have a bat roost in your house or bats visiting your garden, you would not normally be close enough to be an infection risk to them. You do not need to take any extra precautions unless you find a grounded bat that needs help. Current research suggests at least three types of bat could in theory be susceptible to infection from the human coronavirus (12, 13). If you do find a bat in need of help, you should not handle it unless you are qualified to do so. Instead, contact your local bat or wildlife rescue organisation and ask for help.
Bat workers or rescuers who come into close contact with bats should take precautions just as they would for other disease transmission. Please see the IUCN BSG COVID-19 guidance for bat rehabilitators. For information about risks associated with pets, please see the World Organisation for Animal Health (OIE) website (the animal equivalent of the World Health Organisation). You should not care for an animal if you are feeling unwell or think you might have COVID-19.
References
1. Mollentze & Streicker (2020) Viral zoonotic risk is homogenous among taxonomic orders of mammalian and avian reservoir hosts. Proceedings of the National Academy of Sciences. https://doi.org/10.1073/pnas.1919176117
2. Centers for Disease Control and Prevention (CDC) (2020) Human Coronavirus Types. https://www.cdc.gov/coronavirus/types.html
3. Wu et al (2020) A new coronavirus associated with human respiratory disease in China. Nature. https://doi.org/10.1038/s41586-020-2008-3
4. Zhou et al (2020) A pneumonia outbreak associated with a new coronavirus of probable bat origin. Nature. https://doi.org/10.1038/s41586-020-2012-7
5. Andersen et al (2020) The proximal origin of SARS-CoV-2. Nature Medicine https://doi.org/10.1038/s41591-020-0820-9
6. Boni et al. (2020) Evolutionary origins of the SARS-CoV-2 sarbecovirus lineage responsible for the COVID-19 pandemic. Nature Reviews; Microbiology. https://doi.org/10.1038/s41564-020-0771-4
7. Cui et al. (2019) Origin and evolution of pathogenic coronaviruses. Nature Reviews: Microbiology. https://doi.org/10.1038/s41579-018-0118-9
8. Plowright et al (2017) Pathways to zoonotic spillover. Nature Reviews Microbiology. https://doi.org/10.1038/nrmicro.2017.45
9. Woolhouse & Gaunt (2007) Ecological origins of novel human pathogens. Critical reviews in Microbiology. https://doi.org/10.1080/10408410701647560
10. Amman et al. (2014). Marburgvirus resurgence in Kitaka Mine bat population after extermination attempts, Uganda. Emerging Infectious Diseases. https://doi.org/10.3201/eid2010.140696
11. Akpan (2020) New coronavirus can spread between humans—but it started in a wildlife market. National Geographic. https://www.nationalgeographic.com/science/2020/01/new-coronavirus-spreading-between-humans-how-it-started/
12. Luan et al. 2020. Spike protein recognition of mammalian ACE2 predicts the host range and an optimized ACE2 for SARS-CoV-2 infection. Biochemical and Biophysical Research Communications. https://doi.org/10.1016/j.bbrc.2020.03.047
13. Schlottau et al. 2020. SARS-CoV-2 in fruit bats, ferrets, pigs, and chickens: an experimental transmission study. The Lancet: Microbe. https://doi.org/10.1016/S2666-5247(20)30089-6
