5 March 2020
What exactly is COVID-19? What’s a coronavirus?
Coronaviruses are a large family of viruses, so named because they’re shaped like a ball covered by protuberances that give it a crown-like appearance (from the Latin corona meaning crown). There are many coronaviruses in nature, which are found everywhere, in all kinds of animals (e.g. alpacas, birds, bats, camels, cats, civets, cows, hedgehogs, mice, etc.) including humans. Many coronaviruses are actually harmless to humans. However, some coronaviruses are harmful and can cause illnesses in humans which usually affect the respiratory system, and these illnesses range from mild to severe. The common cold, Middle East Respiratory Syndrome (MERS) and SARS (Severe Acute Respiratory Syndrome) are all caused by coronaviruses. COVID-19 is a respiratory disease caused by SARS-COV-2, a new type of virus that was not previously identified or detected by scientists, hence why it’s referred to as a “novel coronavirus”.
Should I be worried about bats in Malaysia causing a COVID-19 outbreak? If there are bats living near me should they be tested?
NO. So far the SARS-CoV-2 virus (also referred to as nCoV-2019) has NOT actually been detected in bats, and it is NOT known to occur in Malaysian bats. There is NO EVIDENCE of similar viruses, MERS-like viruses, or SARS-like viruses in Malaysian fruit bats (Family: Pteropodidae; including flying foxes Pteropus spp.). Although the SARS-CoV and viruses similar to the new SARS-CoV-2 has been detected in insectivorous bats (Rhinolophus spp.) in China, in Malaysia these bats live away from humans, and avoid contact with humans. Scientific research has no evidence that the SARS-CoV jumped directly from bats to humans; it’s likely that another animal such as civets (which also carry the virus) were involved in the original SARS outbreak due to the conditions found in wildlife markets, where such live animals and their meat were sold. Even when bats are found near humans in houses, villages and urban areas, it’s very rare for humans to catch a virus directly from bats; virus transmission requires direct physical contact such as a bite, scratch, or ingestion of bat bodily fluids. Bats carrying viruses in the wild, undisturbed by people, are a minimal threat to human health; humans have a statistically higher chance of catching diseases from domestic animals such as cats and dogs.
But scientists are saying that SARS-CoV-2 originated in bats?
So far there is NO EVIDENCE showing that the COVID-19 outbreak in humans was caused by bats. Scientists who study viruses and viral diseases (virologists) merely speculated that SARS-CoV-2 originated in bats, because the virus’s genome is very similar to other coronaviruses found in bats, and genome sequencing suggests that bats may be the original ancestral host for the coronavirus family. However, this does not mean that bats are the direct cause of modern coronavirus infections in humans. Indeed, so far there have been no cases of live bats in the wild transmitting harmful coronavirus diseases directly to humans. Usually, a different animal acts as an intermediate host to actually transmit the virus to humans (e.g. pangolins). And, even in cases where a coronavirus may have jumped from a bat to another animal before infecting humans, it is unknown exactly how far back in time this spillover event occurred. It may not have happened recently.
So what caused the COVID-19 outbreak?
Humans. At this point, nobody knows for sure how and why the outbreak happened. We still don’t know how exactly the SARS-CoV-2 virus jumped from animals to humans. We don’t know whether it involved direct contact between humans and animals. We don’t even know whether the outbreak even originated in a wildlife market. There’s a possibility it could have originated earlier outside the market, and was brought to the market later by infected people. While several research papers suggest theories, no solid evidence exists to pinpoint the cause and the origin of the outbreak; these are STILL UNKNOWN.
So the wildlife market isn’t the problem? It’s still OK to hunt and eat wildlife?
Consumption and trade of wild animals, including hunting and killing of wildlife, definitely cause viral spillover and zoonotic disease outbreaks affecting humans. This was the cause of the SARS outbreak, because different animals were brought into close contact with each other and their bodily fluids, in unsanitary conditions, which makes it easier for viruses and diseases to jump from one species to another. These conditions allow animals, that don’t normally interact, to spread diseases to one another. So there’s always a disease risk whenever humans come into contact with animals, or bring animals into contact with other animals, and wildlife markets are particularly high-risk situations. The best precaution is to avoid touching, killing, eating, or trading wild animals (e.g. flying foxes carry Nipah virus, so do you really want to risk infection by eating/hunting them?). Also avoid keeping wildlife as pets.
Such close contact can also happen when wildlife habitats are destroyed or reduced, and the rapid spread of viruses can be facilitated by industrial farming practices that put stressed animals into close physical contact with each other, even within the same species (e.g. in the case of Nipah virus in Malaysia). In Africa, when humans cleared a cave of bats, the bats returned later with much higher rates of Marburg virus infection, and research has already shown that culling actually accelerates the spread of infection rather than preventing it. Therefore, modern zoonotic spillovers and outbreaks are created by humans and human activities, not animals. It’s not the wildlife that’s at fault, it’s people.
But I read media statements from Singapore about a Melaka virus that can be transmitted from bats directly to humans without physical contact?
This is also purely speculative; the scientific evidence of a direct transmission route of this virus from bats to humans is NON-EXISTENT, and therefore the empirical data to prove that this actually happened is weak, inconclusive, and unconvincing. An unidentified bat was reported to fly through a man’s house in mainland Melaka, on the west coast of Peninsular Malaysia, one week before he fell ill with the virus. Virologists then selectively sampled a completely different bat species, Pteropus hypomelanus, on Tioman Island located 32 km off the east coast of Peninsular Malaysia. Moreover, the two coasts of the peninsula are separated by a central mountain range which bats do not cross. NO OTHER animals were actually sampled for the virus, and the possibility of an intermediate animal host was not investigated. But when the Melaka virus was found in the Tioman flying foxes off the east coast, the virologists who conducted the studies prematurely concluded, without concrete evidence, that the unidentified and untested bat on the west coast transmitted the virus. This is still UNPROVEN, and it is important to remember that so far the Tioman flying foxes have NOT transmitted any clinical diseases to the local people living in close proximity to them on the island. On Tioman Island, bats and humans have been co-existing safely for generations.
But can I catch COVID-19 or some other virus by eating/touching fruits that are bat-pollinated, such as durians?
No. Viruses cannot be transmitted in this way. These coronaviruses cannot grow in plants. Bats and durian trees have a unique co-evolutionary relationship, where the durian tree has been depending on bats for thousands of years to pollinate its flowers in order to produce healthy fruits. Humans have been consuming durian fruits, enjoying the results of this bat pollination process, for thousands of years without catching viruses from bats. Indeed, many plants need bat pollinators in order to successfully produce healthy fruits and reproduce, and therefore fruit bats play a very crucial role in maintaining healthy ecosystems. In general, you will not catch a virus from bats visiting any flowers/fruits in trees to feed, as long as you do not touch, disturb, or come into physical contact with the bats and their bodily fluids. If any physical contact occurs, wash up with water and soap as soon as possible. Do not pick up or eat fruits that have been partially eaten and dropped by bats.
What about researchers that are catching and handling bats? Could they cause outbreaks?
Scientists that study bats, such as those of us in Rimba’s Project Pteropus, follow health and safety guidelines which include getting appropriate vaccinations, and wearing suitable Personal Protective Equipment (PPE), such as gloves, to touch and handle bats. We do not catch or handle bats without getting relevant training, and prior approval and permits from the authorities. Thousands of scientists across the world catch and handle bats safely everyday.
If I have bats living near me or that come near me, how do I keep myself safe from viruses and diseases?
It’s very simple and easy to co-exist safely with bats – if you leave bats alone and keep your distance from them, the risk of disease transmission is incredibly low. If you try to kill, disperse, or interact with bats, you could actually increase the risk of virus transmission. When animals are happy and calm they are less likely to transmit viruses, whereas the risk of virus transmission is higher when animals are stressed and panicked. Culling bats is never a solution for disease control, as research has shown that this is ineffective since it can actually increase the risk and speed of disease transmission. Follow these simple guidelines to co-exist safely with bats:
- Avoid physical contact with bats – do not touch, catch, kill or eat them. If you are scratched or bitten by a bat, consult a doctor.
- Avoid direct contact with bat bodily fluids e.g. faeces, urine, saliva – if contact occurs, wash off as soon as possible with water and soap.
- Avoid eating or touching fruits that have been directly touched, eaten and dropped by bats.
- Avoid standing under roosting or feeding bats – do not disturb or harass bats.
- If bats are roosting in your house, consult an expert before trying to remove them.
- ‘Coronavirus Disease 2019 (COVID-19)’ – https://www.cdc.gov/coronavirus/2019-ncov/faq.html
- ‘What Is A Coronavirus?’ – https://www.sciencealert.com/coronavirus
- Bat Conservation International’s FAQ on ‘Bats, Coronaviruses, and Zoonotic Disease’ – http://www.batcon.org/resources/media-education/news-room/gen-news/80-latest-news/1227-bci-s-faq-on-bats-coronaviruses-and-zoonotic-disease
- Wildlife Health Australia’s ‘Novel Coronavirus 2019 (COVID-19)’ Fact Sheet – https://wildlifehealthaustralia.com.au/Portals/0/Documents/FactSheets/Public%20health/Novel_coronavirus-2019.pdf
- ‘Wuhan Coronavirus Leads to More Premature Scapegoating of Bats’ – https://www.merlintuttle.org/2020/01/30/wuhan-coronavirus-leads-to-more-premature-scapegoating-of-bats/
- ‘Coronavirus and bats’ – https://batconservationtrust.blogspot.com/2020/02/coronavirus-and-bats.html
- ‘”This is not the bat’s fault”: A disease expert explains where the coronavirus likely comes from’ – https://www.vox.com/science-and-health/2020/2/12/21133560/coronavirus-china-bats-pangolin-zoonotic-disease
- ‘Give Bats A Break’ – https://issues.org/give-bats-a-break/
- ‘Living Safely With Bats’ booklet by EcoHealth Alliance – https://www.ecohealthalliance.org/wp-content/uploads/2018/10/Living-Safely-with-Bats_download.pdf
- Wong M.C., Cregeen S.J.J., Ajami N.J. and Petrosino J.F. 2020. Evidence of recombination in coronaviruses implicating pangolin origins of nCoV-2019. doi:10.1101/2020.02.07.939207. https://www.biorxiv.org/content/10.1101/2020.02.07.939207v1.full
- Olival K.J, 2016. To cull, or not to cull, bat is the question. EcoHealth 13(1): 6-8. doi: 10.1007/s10393-015-1075-7.
- Swift L., Hunter P.R., Lees A.C. and Bell D.J. 2007. Wildlife trade and the emergence of infectious diseases. EcoHealth 4(1): 25-30. https://link.springer.com/content/pdf/10.1007/s10393-006-0076-y.pdf
- ‘Coronavirus not detected in bats and other animals in Singapore so far’. Straits Times, 26 February 2020. https://www.straitstimes.com/singapore/environment/coronavirus-see-a-bat-no-need-to-panic-say-experts
- Chua K.B., Crameri G., Hyatt A., Yu M., Tompang M.R., Rosli J., McEachern J., Crameri S., Kumarasamy V., Eaton B.T. and Wang L.F. 2007. A previously unknown reovirus of bat origin is associated with an acute respiratory disease in humans. Proceedings of the National Academy of Sciences USA 104: 11424-11429.
- Chua K.B., Voon K., Crameri G., Tan H.S., Rosli J., McEachern J.A., Suluraju S., Yu M. and Wang L.F. 2008. Identification and characterization of a new orthoreovirus from patients with acute respiratory infections. PLOS One 3: e3803.
- Chua K.B., Voon K., Yu M., Keniscope C., Abdul Rasid K. and Wang L.F. 2011. Investigation of a potential zoonotic transmission of orthoreovirus associated with acute influenza-like illness in an adult patient. PLOS One 6: e25434.