Good afternoon. My name is Dr. Cameron Jones, and I'm an environmental microbiologist, and welcome to this week's edition of The Mould Show. A little bit like the rent-free period, and mortgage holidays that are happening all over the world, we are going to have a holiday from mould this week, mainly because the SARS-CoV-2 is such a severe pandemic, there is so much interesting information coming out, pretty much on a daily basis, that I've got quite a lot to talk about today. And one of the very interesting stories which has been emerging in the last several weeks is really going to be the topic of what we're focusing on today, which is, can my pet get COVID-19? Now this is really quite an emotional topic for many people, simply because there've been some very disturbing stories coming out of China about the humane or inhumane handling of animals, and also we don't necessarily want to be fearful of our pets. However, it is very important that we definitely do look into what the literature says, and what the emerging trends are in terms of infectious diseases and the spread of COVID-19 within animal populations.
So that's what we are going to be focusing on today. And really, the central topic is can my pet transmit SARS-CoV-2? And yesterday, in the literature, it was reported that a pet in Hong Kong, a pet cat had tested positive for COVID-19. Now, the week before, another cat in Belgium was reported to have also tested positive for the virus. And in fact, several dogs in quarantine in Hong Kong have also tested positive. And in fact, there has been an excellent publication first published in French, with an English language translation for the results for this. And it's particularly disturbing, because the original notification for whether or not COVID-19 was transmitting in pets originally was reported in a Pomeranian dog, and then a German Shepherd. Now, this particular publication, I've got the Earl at the very bottom of this, and again as always I'm going to put all the electronic resources in these show notes at the end, so that everyone who is watching this or listening to the podcast can follow-up all the references that I'm going to be citing.
But one of them, as I said, came out, and it was the scientific committee was looking at this issue of whether or not SARS-CoV-2 virus, what happened to these two dogs in Hong Kong, and the one cat in Belgium? And basically, their conclusion was that on the basis of the data that they were provided with, that the contamination of animals by man appeared to be low, but they did recommend that veterinary services remain highly vigilant, and they encourage epidemiological investigations to all new cases. So it would appear that there doesn't seem to be any significant risks to humans from picking up COVID-19. Although there are this handful cluster of cases which suggests that there has indeed been some sort of positive transmission, either human to animal, but the bigger question is, could it be animal to human? In any case, the conclusion that the committee came to was that the risk of infection of man from animals... essentially, they're not in a position to determine that risk.
So they didn't really form any opinion at the end of the testing, even though the virus was detected in the PCR tests that were done on certainly the dogs over a couple of week period in quarantine. Now, if we look further into this whole topic, there are over 150 million dogs and cats in the United States alone. A microbiologist at the University of Pennsylvania School of Vet Medicine, she said that if there were in fact a lot of cases of animal transmission or COVID-19 disease was occurring in a widespread population of the dogs and cats, well, vets would be seeing evidence of respiratory infections at this stage, or at least that was her conclusion. But I'm going to be talking about some breaking research, which has just come out overnight in a few minutes. So bear with me, and stick with me. Now, one particular laboratory in the United States, IDEXX Reference Laboratories, they are actually primed and ready to go with testing of animals across the United States. If the United States Department of Agriculture changes their position. And what do I mean by their position?
Well, at this point in time, they said last week that at this time, testing of companion animals will only be done if the animal and public health officials agree the testing should occur due to a known link with human cases of COVID-19. So in a sense, the labs are ready to start testing domestic pets, but they're waiting for the USDA to indicate or flag fall that there could be a risk. And I suggest that that is possibly going to occur due to the research which has come out overnight on a preprint server if all of their data checks out and is properly validated. Now I want to digress just a little bit. Now I see that that is just moved across. If we look at a very interesting recent paper that came out looking actually into the psychology of people in Italy, and the reasons that they actually used to leave home, you'll find in a very interesting graph that they published that actually going to walk your pet occurs at a percentage of 6.3%. so it really the fourth most dominant reason for leaving the house in Italy, at this point in time.
And as we all know, they have a severe spread of COVID-19 throughout their population. Obviously, the most, or the dominant reason for leaving the house is to get food for the family. Next, to go to the pharmacy, third go to work, but the next one was to walk the pet. And that came in on an equal percentage footing with taking care of dependent children. So you can see that the way people are behaving is that they really do need to walk their pets. And that this is another chain in the evidence for why this could be a huge problem down the track. So the epidemiology of this is absolutely fundamental to get to the bottom of. Now, what does the CDC say? Well, they are still adamant that if you have animals, there is no to negligible risk. And I think that that's a good thing, at least at this point in time until the paper that I'm about to talk about checks out. If it does check out, I think that the CDC probably needs to revisit their recommendations.
So what did the latest paper show from the 31st of March? Well, I've put the URL up here, because I'm sure a lot of you pet owners are going to want to download it for yourself. It is free. You can jump on to the preprint server, and download a copy yourself. And what they said is that susceptibility of cats, dogs, and even ferrets, and other domestic animals for SARS-Coronavirus-2. That's the topic or the core group of animals that were being investigated. That's the title of their paper up there. And what they concluded was that SARS-CoV-2 does in fact replicate poorly in dogs, pigs, chickens and ducks, but efficiently in cats and ferrets. So, their conclusion was that virus transmits in cats via respiratory droplets, and their study provides important insight into which animal reservoirs for SARS-CoV-2, and other types of animal management that may need to be undertaken, enforced, or examined for quarantine as we deal with controlling COVID-19. Now, we're going into our usual segment, which is the breaking news.
And, I want to pull up this article here that also was published just a couple of days ago, because we're hearing a lot about needing to undertake social distancing, and maintain an adequate distance from other people. A fascinating paper has come out suggesting that the spread of droplets when someone coughs or sneezes, which remember that is the dominant way in which this virus is going to be transmitted from person to person, through droplets spread. When the scientists actually examined how far these droplets move, you can see that it is a lot further than the one to 1.5 meters, which is the suggested distance that individuals should maintain as a safe distance between one another. And the research showed that the droplets transmit seven to eight meters. Now in this next slide, I'm going to actually play you a little bit of the video that was in the supplementary material to the research article that they published, because it shows very clearly exactly what is occurring when someone sneezes, and it is very visually compelling.
So I will pull this up now, and show this to you. The first part of the video demonstrate someone coughing, and you can see in the way that they photograph this, you can see the actual distance that the droplets spread. For copyright reasons, obviously I'm speaking over the top of this, but I'll give you a few seconds to see this. And now we're looking at another example of this. So these are the droplets which then end up settling out onto surfaces. And as we saw last week, that the RNA virus which is present on these droplets is able to remain viable on surfaces. And as we saw, obviously copper surfaces are reasonably able to deactivate the RNA, whereas cardboard and plastic, the virus can remain viable for even more than three days. And some other research showed in fact that the virus could remain recoverable, and maintain its viability for up to 17 days. So, now that you've seen that, I'd encourage you to look into that research paper, because it has a lot to say about aerosolization of viral particles, and also sedimentational settling out onto surfaces.
I just want to reiterate what the Australian government is expecting every individual to comply with, which is the social distancing education, and of course to maintain at least 1.5 meter distance from one another. And I would suggest that as the scientific research like I've just demonstrated to you, as that becomes more widely known, people are probably going to maintain even longer or larger distances from one another. Again, there is some very useful information on the WhatsApp provided by the government as well, and that also shows some excellent statistics on a day-by-day basis. I would now want to talk about this issue of face masks. Certainly people have been calling me and sending me emails. What's my opinion on face masks? Should they be used? They don't work because the type of material is still going to allow virus particles which are smaller than the 0.3 microns to get through. Certainly I've looked into this topic quite extensively in the last couple of weeks. I've looked at what the World Health Organization has to say.
They are still maintaining that you don't necessarily need to wear masks unless you are sick, or you are coming into contact with individuals who are sick. But I want to sort of take a lens and focus on this topic in some greater depth now, and point out some papers which have also come out in the last 24 to 48 hours, which are probably suggesting that we need to re-look at whether or not masks should be used as a preventative measure. And at the end of the day, my opinion is that they certainly can't hurt you, and that we really need to take this matter very seriously when we go out in public. So what does the latest research say? And in order to do justice to this, I've pulled out a publication, which as I said just appeared in the academic literature, and the title of this is COVID-19: Face Masks and Human-to-Human Transmission.
Now this is a letter to the editor, and I'm going to be reading through actually what the author had to say, because these are epidemiologists, and they are talking about what happened in China when an individual travelled on public transport with and without a mask. And I think it's very illuminating, because it's very clear to understand from this description exactly how transmission occurs when sick individuals travel with other people, the significant potential to transmit the virus to other people. So the scientists stated that they are reporting on a cluster outbreak which occurred on public transport. That one patient in China didn't wear a face mask in the first part of his journey, and he did wear a face mask in the second part of the journey. It was a male, and he found himself coughing. He was unaware at that stage that he might be infected with COVID-19. And he reported when he was discussing this after the fact that he was in fact in a hurry, and he didn't manage to get a face mask before he took the coach bus from the city back to his particular county.
He reports that many passengers didn't wear face masks who were on the same coach as him. The duration of his trip was two hours and 10 minutes. Now, there were 39 other passengers in the same coach bus. Now, the epidemiological survey that was carried out, there were five other passengers on the same coach who were also infected. Now, when he got to his destination, the male patient bought a face mask, and then he took a minibus to his final destination, but wearing the mask. So the duration of the minibus trip was 50 minutes. And on that minibus, there were 14 other passengers. When the Center for Disease Control and Prevention did the epidemiological investigation, they did contact tracing to work out where all these individuals ended up. Now the passengers on the mini bus were screened, and they were treated as suspected cases, and the 14-day medical observation period was undertaken. Now, during the observation period, they had their temperatures taken twice per day, and they were asked whether or not they did or did not experience respiratory symptoms, as well as fever, dry cough, and any digestive issues such as diarrhea.
All of the passengers did not have fever, cough, or other abnormal symptoms. However, two qPCR test results were negative. No passengers were infected who travelled on the minibus. The conclusion, however, is that this particular patient transmitted COVID-19 to five people on the one vehicle when he was not wearing a face mask. This is really, really important. And in fact, the authors cite the fact that the Australian federal government has released half a million face masks to general practitioners, and other health workers across Australia to protect them from infection by COVID-19. And the conclusions that this scientist is making is that wearing face masks protects yourself and others. Use of face masks therefore is likely to play a vital role in mitigating disease spread. This is really important, and I urge anyone who is on the fence about the importance of masks to at least review what is in these really new publications, and consider the fact that droplet transmission spread will in fact be reduced by wearing masks. The issue of availability of masks is something that I'm not going to cover as part of my discussion here.
Now, I've already gone through the summary of the conclusions here. So I'll put them up on screen. Anyone who is undertaking any type of use of public transport, I certainly encourage them to follow the conclusions that the scientists make in this paper, and wear masks on public transport. And of course, if you are traveling with anyone with known symptoms of COVID-19, who are suffering from that particular disease caused by SARS, well, definitely wear a mask. So, they also encourage susceptible individuals or people who want to take care to travel with at least one or two extra masks. What do other people have to say in the contemporary media landscape? Well, the Financial Times have done a fantastic job of data modelling the SARS-CoV-2 epidemic. And, someone I encourage you to follow on Twitter, John Burn-Murdoch has published some fantastic data visualizations. And the reason I'm highlighting him is that he's responsible for this modelling, and yet out on the Twitterverse, other individuals have taken some of his graphs, and they themselves have made their own interpretations in it, and some of those interpretations predate the paper that I just discussed about the importance of masks.
And they are showing with his data that some countries that don't advocate or encourage wearing of masks have quite a high number of new cases. Whereas some other countries, especially those that have a history of already wearing masks, because they've had a history of pre-existing earlier SARS-type virus, influenza outbreaks, they are conditioned to wear masks, and often for combating pollution as well. And those countries seem to have a different rate of transmission, which is very interesting. And of course it's been seized on by various different social media authors. Now, what is the latest research showing about face masks? Well, again, another wonderful paper came out yesterday talking about wearing face masks, in combination with hand hygiene, or using sanitizer. And in their paper, they were looking at three different types of masks, the well-known N95 mask, medical masks, and then even homemade masks. And they discovered that the ability of these masks to resist the aerosol virus-containing aerosol was 99.98% for the N95, 97.14% for the medical mask, and even the homemade mask protected the individual at a percentage of 95.15%.
So their conclusion was a combination of hand hygiene, using instant hand sanitizer, in combination with masks ends up slowing the exponential spread of this particular virus. In any case, that brings me to the end of today's Mould Show. Obviously, there's a lot I'd like to say about some wonderful research that also came out this week, talking about the spread of different fungal and bacterial microorganisms. Often when we do spore traps in domestic residences, we do it on a tripod to capture the mould levels in the breathing zone. Well, a paper that I'm probably going to talk about next week was discussing what happens at much higher elevations. And they found that these fungal and bacterial particles are present at very high distances off the ground as well. So there is a rich microflora of other microorganisms all around us. I'm focusing a lot on SARS-CoV-2, but we mustn't forget the widespread effect that microorganisms are all around us.
Some other research about the transmission of SARS in Italy is suggesting that the hardest-hit areas have the worst pollution, and the conclusions in some of this emerging research, their hypothesis is that the high levels of PM2.5, and PM10 particulate matter could be reservoirs where the virus has been able to be transmitted quite widely, or adversely impacts on the respiratory health of those individuals in those particular towns and cities. In any case, my name's Dr. Cameron Jones. I'm an environmental microbiologist. Feel free to send me any questions that you'd like me to cover next week. I hope you have a very good week. Stay safe, maintain the social distancing, and follow all the public health news and warnings that you can safely use to protect yourself as best as is possible. Bye for now.
Chen H. Susceptibility of ferrets, cats, dogs, and different domestic animals to SARS-coronavirus-2. 2020. doi:10.1101/2020.03.30.015347
Barari S, Caria S, Davola A et al. Evaluating COVID-19 Public Health Messaging in Italy: Self-Reported Compliance and Growing Mental Health Concerns. medRxiv. 2020;(March 30). doi:10.1101/2020.03.27.20042820
Pet dog tests positive for COVID-19 virus, Thursday, March 19, 2020. Afcd.gov.hk. https://www.afcd.gov.hk/english/publications/publications_press/pr2346.html. Published 2020. Accessed April 1, 2020.
Bertrand S, Buntinx M, Clinquart A et al. Risque zoonotique du SARS-CoV2 (Covid-19) associé aux animaux de compagnie : infection de l’animal vers l’homme et de l’homme vers l’animal (Mandat du Comité scientifique fédéral en charge de la gestion de la pandémie de SARS-CoV2 en Belgique). Afsca.be. http://www.afsca.be/comitescientifique/avis/2020/_documents/Conseilurgentprovisoire04-2020_SciCom2020-07_Covid-19petitsanimauxdomestiques_27-03-20_001.pdf. Published 2020. Accessed April 1, 2020.
Detection of low level of COVID-19 virus in pet dog. Info.gov.hk. https://www.info.gov.hk/gia/general/202002/28/P2020022800013.htm. Published 2020. Accessed April 1, 2020.
Ketchell M. Hong Kong dog causes panic – but here's why you needn't worry about pets spreading COVID-19. The Conversation. https://theconversation.com/hong-kong-dog-causes-panic-but-heres-why-you-neednt-worry-about-pets-spreading-covid-19-133304. Published 2020. Accessed April 1, 2020.
Coronavirus Disease 2019 (COVID-19) - If You Have Animals. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/daily-life-coping/animals.html. Published 2020. Accessed April 1, 2020.
Grimm D. Should pets be tested for coronavirus?. Science. 2020;Mar. 31(2020). doi:10.1126/science.abc0029. https://www.sciencemag.org/news/2020/03/should-pets-be-tested-coronavirus
Pet cat tests positive for coronavirus in Hong Kong. The Straits Times. https://www.straitstimes.com/asia/east-asia/pet-cat-tests-positive-for-coronavirus-in-hong-kong. Published 2020. Accessed April 1, 2020.
Bryner J. Cat infected with COVID-19 from owner in Belgium. livescience.com. https://www.livescience.com/cat-infected-covid-19-from-owner.html. Published 2020. Accessed April 1, 2020.
Follow-up reports: Immediate Notification, then Reports No.1,2 and 3. Oie.int. https://www.oie.int/wahis_2/public/wahid.php/Reviewreport/Review?page_refer=MapFullEventReport&reportid=33546. Published 2020. Accessed April 1, 2020.
Questions and Answers on the COVID-19: OIE - World Organisation for Animal Health. Oie.int. https://www.oie.int/en/scientific-expertise/specific-information-and-recommendations/questions-and-answers-on-2019novel-coronavirus/. Published 2020. Accessed April 1, 2020.
Bourouiba L. Turbulent Gas Clouds and Respiratory Pathogen Emissions: Potential Implications for Reducing Transmission of COVID-19. JAMA. Published online March 26, 2020. doi:10.1001/jama.2020.4756
Liu X, Zhang S. COVID-19 : Face Masks and Human-to-human Transmission. Influenza Other Respir Viruses. 2020;(29 March 2020). doi:10.1111/irv.12740
Ma Q, Shan H, Zhang H, Li G, Yang R, Chen J. Potential utilities of mask wearing and instant hand hygiene for fighting SARS-CoV-2. J Med Virol. 2020;(31 March 2020). doi:10.1002/jmv.25805
MORE NEWS ON ANIMALS AND COVID-19 AND OTHER CORONAVIRUS:
Mallapaty S. Coronavirus can infect cats — dogs, not so much. Nature.com. https://www.nature.com/articles/d41586-020-00984-8. Published 2020. Accessed April 3, 2020.
Coston M. Susceptibility of Ferrets, Cats, Dogs & Other Domestic Animals to SARS-CoV-2. Afludiary.blogspot.com. https://afludiary.blogspot.com/2020/04/susceptibility-of-ferrets-cats-dogs.html. Published 2020. Accessed April 4, 2020.
Lun ZR, Qu LH. Animal-to-human SARS-associated coronavirus transmission?. Emerg Infect Dis. 2004;10(5):959. doi:10.3201/eid1005.040022
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