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Researchers look into increasing incidents of Covid-19 in animals in SL
In addition to humans, several other types of animals, including ferrets, cats, dogs, and civets, are also prone to contracting Covid-19 [/caption]
Coronavirus-infected lions, bats in Sri Lanka
It was reported early this month that an 11-year-old lion at the Dehiwala Zoological Gardens had tested positive for Covid-19, and that the lion had shown symptoms such as breathing difficulties. According to the zoo officials, they are currently monitoring the lion, while PCR tests have also been conducted on the employees of the zoo. It was later reported that the authorities were seeking the assistance of India, which had reported incidents of Covid-19 among lions in the recent past.
This is the first case of a Covid-19-infected animal reported from Sri Lanka, which brought to light the fact that animals too can contract different types of coronaviruses including Covid-19. This was further emphasised by a study submitted this year, conducted by several researchers including Sri Lankan researchers, which noted the detection of two types of coronaviruses in bats found in Sri Lanka.
The two coronavirus types, namely Alpha-Coronavirus and Beta-Coronavirus, had been found in two species of Sri Lankan bats, namely, the Eastern Bent Wing bat (Miniopterus fuliginosus) and Leschenault's Rousette (Rousettus leschenaultii).
A total of 255 rectal swabs and 141 faecal samples from different bat species were tested by using the adapted nested PCR protocol for the generic detection of Coronaviruses, and a total of 33 samples had proven positive. The study provided the first molecular biological analysis of different viruses in bat species roosting in the Wavul Galge cave in Sri Lanka, and the researchers had detected Alpha-Coronavirus in the Eastern Bent Wing bat and the Beta-Coronavirus in the Leschenault’s Rousette. The results of the study indicate that different virus strains are persistently present within both populations.
However, researchers said that the detailed gene and genome analysis of the existing coronaviruses, as well as further studies with a focus on the other sympatric (in the same geographic area) species might provide more insight into the prevalence, circulation, or persistence of different coronavirus strains in this cave.
The study report noted that a long-term study would be helpful to examine the seasonal shedding of the viruses and the impact of migration behaviour of the different bat species, while the results of the study indicate that the detected coronaviruses are host-specific for the respective bat species and, that despite the sympatric cohabitation in the Wavul Galge cave, incidences of inter-species transmission were not observed.
It further added: “This supports the assumption that only particular bat species serve as a natural reservoir for harmful human pathogenic viruses like the Severe Acute Respiratory Syndrome Coronavirus, while spill-over events may occur because of environmental impacts and the intrusion of humans to the living areas of the bat species. Studying bats and monitoring their viruses, as well as the respective interaction with their natural habitats, are both important factors to better understand and prevent zoonotic transmission from bats to humans. Being the largest cave in Sri Lanka with as many as five sympatric bat species, numbering over 100,000 individuals, the Wavul Galge Cave provides an excellent natural site for the long term monitoring of bat-borne viruses in Sri Lanka.”
Researchers emphasised that this study highlights the need to periodically monitor all bat species and their viruses in the said cave.
Though The Morning attempted to contact some of the researchers attached to the study, they were not available for immediate comment.
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All who own domestic animals, especially pets, must be vigilant about the warning signs and to take prompt measures to protect their animals[/caption]
Covid-19 transmission: animal to human and vice versa
With the aforementioned developments, many became more concerned about the possibility of the transmission of Covid-19 between humans and animals. The assumption that infected animals can transmit the virus to humans, in fact, was first discussed in the early stages of the pandemic, as some said that Chinese nationals consuming wild game were the reason behind the beginning of the pandemic.
Sri Lanka Veterinary Association (SLVA) General Secretary Dr. G.S. Premachandra said that even though bats may be infected with Covid-19, the possibility of it affecting humans (transmitting to humans) is extremely minimal.
He added that there are a number of variants of the virus, and that even though animals including cats and dogs may contract the virus, no research conducted thus far has confirmed that the virus can be transmitted to humans through them. He noted that therefore, there is no reason to entertain unnecessary fear. He added that there is no reason for people to abandon their domestic animals such as cats and dogs, as it has not been scientifically proven that humans can contract Covid-19 from animals.
“Covid-19 cases among humans are not caused by the variants prevalent among animals,” he said, adding that matters pertaining to such are currently being investigated. He explained that there is, however, a possibility that specific variants of the virus may mutate into a new variant during the transmission between animals and humans, and that this is one of the main reasons why the public is advised to act vigilantly.
He added: “If there are Covid-19-infected persons in the house, they should refrain from touching and kissing their pets, because animals can still contract the virus from humans. Lions at the Dehiwala Zoological Gardens are believed to have contracted the virus from the person who looks after them. Even though there is a possibility of the virus spreading among animals, adequate reasons have not been found to suggest its transmissibility.”
Dr. Premachandra noted that the Peradeniya University is conducting studies about the matter. “However, no proof has been found to suggest such a thing, and Covid-19 is a disease that spreads primarily among humans. But, if domestic animals, especially pets, show symptoms such as coughing, fever, breathing difficulties, lethargy, sneezing, nasal discharge, ocular discharge, vomiting, and diarrhoea, they should be taken to the nearest vet and be subjected to the necessary tests,” Dr. Premachandra explained, adding that tests are usually conducted at a laboratory at the Peradeniya University, which has the necessary facilities.
Meanwhile, the State Veterinary Surgeons Association (SVSA) also said in a statement that there is no reason to fear animals spreading Covid-19, as no scientific study has found that the coronavirus existing in animals can transmit to humans. They noted that coronavirus in animals is not a new development, and that variants of the virus have been reported from as far back as the 1930s. They also noted that several local institutions are conducting experiments in this connection.
The SVSA also noted that according to the studies that have been conducted so far, a direct link between the coronavirus that causes Covid-19 and coronavirus variants detected in animals has not been established.
Speaking to The Morning, SVSA Secretary Dr. Nuwan Hewagamage said that animals having different variants of the virus is quite normal.
The global situation
However, the issue of animals contracting Covid-19 appears to be an evolving situation, as several countries, including neighbouring India, have reported similar cases.
Early this month, the second Covid-19-infected lion in Indian zoos died, while 10 other lions continue to receive treatment for Covid-19. Some media reports claimed that this situation suggests that big cats in zoological facilities may be more vulnerable to Covid-19 than previously thought. The second deceased lion had tested positive for Covid-19 on 3 June, along with several other lions, and had been showing symptoms such as breathing difficulties and loss of appetite. Last month, eight Asiatic lions tested positive for Covid-19 at the Nehru Zoological Park in Hyderabad, India, and most of them had recovered from Covid-19 or responded positively to treatment.
According to researchers, in addition to humans, several other types of animals, including ferrets, cats, dogs, and civets, are also prone to contracting Covid-19.
An analysis of 10 species of animals, of which Spain’s Centre for Genomic Regulation Director Luis Serrano was a part of, had found that ducks, rats, mice, pigs, and chickens were less susceptible to the virus that causes Covid-19.
“Though we also find a potential susceptibility to infection by cats, they do not co-exist with humans in the same conditions as other animals, which may explain as to why so far there are no known cases of people being infected by their pets,” he had told foreign media.
Even though medical experts have claimed that vaccines can protect against all variants of the virus that cause Covid-19, and that the virus’ highly contagious nature is the main reason it is difficult to contain, a substantial amount of knowledge about the virus and Covid-19 appears to be changing. Researchers have made new discoveries about the symptoms, post-Covid-19 diseases, and the virus’s aggressiveness in the past few months, and most of these new findings are applicable to Sri Lanka as well. However, it was only recently that Sri Lanka paid attention to the virus being spread to and among animals.
It is true that the critical matter at hand is managing the spread of the virus among humans, and that research conducted so far has not proven that infected animals can transmit it to humans. However, in a context where further research is being conducted in this regard, one cannot be too careful, especially due to the evolving nature of the virus.
Importantly, the veterinarians that spoke with The Morning said that animals can contract the virus from humans, and that therefore, there is a duty for all who own domestic animals, especially pets, to be vigilant about the warning signs and to take prompt measures to protect their animals. Also, due to the possibility of the virus spreading among animals, it is also vital to keep sick domestic animals separate from healthy ones.