With Covid-19 in mind, NParks researchers keep tabs on bats

Since 2011, a group of researchers from the National Parks Board (NParks) has set out from time to time to spots around the island to collect urine and faecal samples of bats and test for a number of viruses.

That practice has taken on even greater significance since early last year, when the samples have also been tested for the Covid-19 virus.

Speaking to The New Paper recently, Dr Chang Siow Foong, group director of professional and scientific services at the NParks' Animal and Veterinary Service (AVS), said bats are reservoirs for viruses, including coronaviruses, and revealed that steps are being taken to ensure that the population of the mammal here does not pose a threat.

Said Dr Chang: "The current understanding by the World Organisation for Animal Health (OIE) is that Sars-CoV-2, the virus responsible for Covid-19, is believed to have emerged from an animal source, which then spilled over to humans.

"To ensure that our local wildlife populations are safe from the threat of biological diseases, we have been testing biological samples from bats for various types of viruses, including Sars-CoV-2."

If members of the public stumble on a sick bat or a bat carcass and inform NParks, its researchers will get to the animal and collect an oral sample by swabbing it and conducting a polymerase chain reaction (PCR) test.

NParks said no bat samples have tested positive for Covid-19 to date.

It said bats are generally harmless. They are an important part of Singapore's urban and green landscape as the mammals are pollinators of edible plants and feed on mosquitoes, beetles and moths, thus helping to keep insect populations in check.

While the prevalent theory is that the virus first appeared in an animal, there is also concern that humans who have been infected could spread the virus to animals.

While no animals have tested positive here, there have been sporadic reports out of some countries of a small number of animals, including cats, dogs, minks, raccoon dogs and even zoo animals testing positive for Covid-19 after coming into contact with infected individuals.

In April, the Veterinary Research journal reported two cases of human-to-cat Covid-19 transmission in the United Kingdom.

Earlier this month, a nine-year-old lioness at a zoo in Chennai, India, was infected with the virus and died. It was among nine lions there that had tested positive for the disease.

Dr Chang said the AVS keeps in close contact with the OIE and reviews any new information that surfaces.

He added: "The current Covid-19 spread is still predominantly due to human to human transmission. While there have been some cases of animals getting the virus, these are rare."

In treating a sick pet of a Covid-19 patient, he explained that a veterinarian will first assess the exposure risk of the animal and rule out other more common causes of illnesses.

Dr Chang said: "Should the veterinarian suspect that the animal may have Covid-19, the veterinarian will contact AVS.

"AVS will follow up with the owner of the animal and the veterinarian to conduct further testing and isolation of the animal as needed. If required, AVS will collect samples from the animal and use a PCR test method for animals recommended by the OIE."

These tests require specialised equipment and test reagents and are best carried out by a laboratory instead of at a veterinary clinic, he added.

MONITORING

NParks has been monitoring bats since 2011 as part of its biosurveillance programme which is used to study Singapore's animal populations and detect animal diseases.

Said Dr Chang: "NParks' biosurveillance programmes for animals cover both companion animals and wildlife.

"Biosurveillance is conducted through reporting of clinical cases from veterinarians and collection of samples obtained from animals. Samples may be obtained opportunistically or through investigations and are tested using methods recognised by OIE."

Local biosurveillance programmes will be reviewed based on the latest scientific evidence to ensure they remain viable.

To prevent the transmission of diseases from animals, Dr Chang said good hygiene, with thorough handwashing before and after direct contact with pets, their supplies and food, is essential.

"Persons who are unwell should also limit their contact with their pets, as they would with other people," he added.