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There have been reports of a tiger in New York that has tested positive for COVID-19.
Dr Steve Unwin, Lecturer, School of Biosciences, University of Birmingham, said:
“The current pandemic is a forceful reminder of the need to treat global health as a system linking human, non-human animal and environmental health. By looking beyond the source and focusing on the drivers of infection at a systems level, we may stand a better chance of preventing or at least minimising the effects of future global health problems.
“Pathogens do not know direction. If the host and environment situation for transmission is right, transmission will occur, regardless of host species. Although the origin of SARS CoV2 remains speculative (https://www.nature.com/articles/s41591-020-0820-9), it is often reported that there is a wildlife reservoir for this disease (https://news.mongabay.com/2020/03/conservationists-set-the-record-straight-on-covid-19s-wildlife-links/). By utilising multidisciplinary skill sets to assess global health threats, we can help highlight the underlying drivers of disease threats like SARS CoV2 to attempt to prevent or at least moderate future outbreaks.
“Some recent examples:
“Often under reported is the effect of zoonotic infection in animals. Recent evidence indicates a variety of species could be at risk from infection with SARS CoV2 from human sources. Some are not yet verified (E.G the recent tiger case at the WCS Bronx Zoo (https://www.aphis.usda.gov/aphis/newsroom/news/sa_by_date/sa-2020/ny-zoo-covid-19?ftag=YHF4eb9d17). Others are confirmed but from other coronavirus types (E.G in wild chimpanzees susceptible to OC43 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6021434/).
“It is currently unknown whether the morbidity and mortality associated with SARS-CoV-2 in humans are similar in our closest relatives – the other apes. However, transmission of even mild human pathogens to apes can lead to severe outcomes, so the risks seem extremely high. We are leading an international network of specialists working with apes in the wild and in captivity. The aim is to collate and disseminate recommended pandemic response protocols and research, both human and animal, (WHO, IUCN, AZA, EAZWV), combined with current response efforts of great ape conservation and welfare organisations to: 1) improve response efficacy and facilitate rapid access to expertise for practitioners that would not otherwise be available, and 2) provide canvas and web based teaching resources for ongoing capacity building on outbreak management and wildlife focused One Health to strength resilience against future outbreaks. These resources, some fully public, some within sector only, will be rolled out from mid-April 2020. We can then start to identify key data gaps for co-ordinated evidence based research in multi species emerging disease threats.”
Dr Amanda Fine, Wildlife Health Programme Associate Director, Wildlife Conservation Society, said:
“This COVID-19 positive test in a tiger at the Bronx Zoo should not be confused with the on-going efforts to determine if a species of traded wildlife may have played an intermediate role in the transmission of SARS-CoV2 from bats to people. With large numbers of people infected with SARS-CoV2 in New York, this case is an example of a human infection spilling over into a captive wild animal that is cared for by humans in a zoo setting.
“Zoo keepers and veterinarians responsible for the health and well-being of the zoo population noted clinical signs and symptoms of disease in the tigers and lions and collaborated with health departments and laboratories in the region to test for COVID-19 knowing it would be important for our global understanding of COVID-19 to confirm whether or not the animals were infected with the virus. The finding indicates that captive tigers can be infected with the SARS-CoV2 virus. For tigers and lions in the wild, this is just another warning that human encroachment into natural habitats must be reduced to ensure the survival of species, and that prevention of transmission of infectious diseases from humans and their domestic species to wildlife is another critical component of wildlife projection.”
Dr Rachael Tarlinton, Associate Professor of Veterinary Virology, University of Nottingham, said:
“It’s not entirely unexpected that big cats or other zoo species might be susceptible to picking up Coronavirus infection from people. There have been a very small number of cases in domestic pets (cats and dogs) that have picked it up from their owners and one experimental study that hasn’t been reviewed yet that indicated that cats might be more susceptible to this. In none of these cases have the animals spread it to people, nor do animals get very ill themselves. It’s important to remember that the number of infected zoo and domestic animals so far has been really small, despite a lot of monitoring and that there isn’t really any reason to think that pet dogs or cats should be treated any differently to any other family member right now.”
Prof Ken Smith, Professor of Companion Animal Pathology, Royal Veterinary College, said:
“The data from the Bronx Zoo stating that four tigers and three lions have shown signs of COVID-19 following contact with an asymptomatic but COVID-19 positive zoo keeper indicate that there is a risk of big cats, like domestic cats, becoming infected with this virus if in contact with infected people (there is the single instance of the pet cat in Belgium that became infected from their owner that also supports this). The important points to stress are: a) that the big cats in the Bronx Zoo have shown mild clinical signs and would be expected to recover; and b) that there is no evidence that naturally infected cats can shed virus in sufficient quantity either to infect other cats or people. These occasional instances of human to animal transmission of COVID-19 do not in any way detract from the fact that all current evidence shows that the pandemic is driven by human to human transmission.
“The key messaging for cat owners, and others responsible for the health and welfare of animals under their care (including in this case zookeepers) concerned to avoid spread of infection from humans to animals is that contact between infected people and other animals should be minimised. Specifically, basic hygiene measures should always be implemented. This includes hand washing before and after being around or handling animals, their food, or supplies, as well as avoiding kissing, licking or sharing food. In the context of pet cats, if cats are present within a COVID-19 positive household, they should be kept indoors.
“This is the link to the statement on the RVC website from last week, which pre-dated the information from the Bronx Zoo but focussed on the same message of balancing public health and animal welfare considerations on a sound evidence base, following a report from China that cats could be experimentally infected with the COVID-19 virus: http://www.rvc.ac.uk/news-and-events/rvc-news/companion-animals-and-covid-19.”
Dr Tara Pirie, Postdoctoral Research Fellow, University of Reading, said:
“With captive tigers and lions testing positive to COVID-19, it highlights a potential risk of infection to their wild counterparts and other cat species. Although the infected animals have mild symptoms, suggesting it may not be as fatal in felines as it is in humans, it would be prudent to confirm this before dismissing it as a possible threat to big cats.
“Many big cats are already endangered and any new disease that can affect them needs to be carefully monitored, or the future existence of these magnificent species could be further threatened. There are few diseases that humans and big cats can both host, some are more fatal to cats (e.g. rabies, anthrax) than others (e.g. toxoplasmosis). However, they can be susceptible to respiratory diseases with 2 tigers and 2 leopards dying at a zoo in Suphanburi, Thailand (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3323383/) and almost half the 102 sick tigers dying at a zoo in Chonburi, Thailand (https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(04)01216-2/fulltext) from the Avian flu H5N1 in 2004.”
Dr Sarah Caddy, Veterinarian and Clinical Research Fellow, University of Cambridge, said:
“A tiger in the Bronx zoo with a dry cough has tested positive for COVID-19. A pre-print released last week found that domestic cats can be experimentally infected with SARS-CoV-2 if large doses of virus are administered intranasally. Therefore the report of a tiger with the same virus is not wholly unexpected.
However, it is surprising that the tiger has become infected with what must have been a fairly low dose of virus – we can assume the tiger did not have continual close contact with the asymptomatic zoo keeper. It is also interesting that the tiger showed clinical signs consistent with COVID-19 in humans. Although scientific proof is lacking, the chance this is just a coincidence is low.
What does this mean for our pet cats? Nothing new – at present there is still only one suspect case where an owner has spread the virus to their pet. It is possible that tigers in captivity are more susceptible to the virus than household moggies as there is a 5% difference between their genomes. The bottom line is that there is no evidence that any cat, large or small, can transmit virus back to humans.”
All our previous output on this subject can be seen at this weblink: www.sciencemediacentre.org/tag/covid-19
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