Expert: Risk of bats in Singapore transmitting Covid-19 low, but precautions still useful

Bats can spread viruses through their faeces. - The Straits Times/Asian News Network

SINGAPORE, Sept 14 (The Straits Times/ANN): It is highly unlikely that bats in Singapore are carrying the coronavirus that causes Covid-19, but people who come into contact with one should still take precautions, two experts said.

For example, residents who have bats flying into their homes should look out for any secretions and contamination from the animal and clean them as soon as possible. This is because bats can spread viruses through their faeces.

Professor Wang Linfa, director of the emerging infectious diseases programme at Duke-NUS Medical School, said: "There is no evidence that bats in Singapore are carrying Covid-19 or related viruses.

"Of course, a negative finding does not prove a complete absence. Hence, it is always a good idea to be on the alert, but there is no need for panic."

Another infectious diseases expert, Dr Leong Hoe Nam, who practises at Mount Elizabeth Novena Hospital, said the possibility of a bat spreading the virus to a human is similar to the odds of striking the lottery. But he also cautioned: "The risk is small but real."

The experts were commenting on the issue following Manpower Minister Josephine Teo's Facebook post last week that residents in Boon Keng were concerned about bats flying into their homes. Teo said the residents were worried about the bats being disease carriers.

But a National Parks Board officer and bat research specialist subsequently assured those affected that the bats are not carriers of virulent strains of the coronavirus.

The Jalan Besar Town Council also pruned fruit trees near the affected block to discourage the animals from roosting there.

Dr Leong said that residents who still find bats flying into their homes could take other precautions, such as wearing an N95 mask and showering immediately.

On whether bats could contract the Covid-19 virus from humans, Prof Wang said that this phenomenon - termed spillback - is possible.

"But again, the risk is very low in Singapore, as the community transmission is at a very low level and the risk of spillback is extremely low," he said.

Prof Wang recently co-authored a paper about the possibility of reverse transmission from humans to wildlife, with a case study done on bats. The paper concluded that there is an unknown, but possible and potentially high-consequence, risk of Covid-19 transmission to North American bats or other free-ranging mammals.

Humans who frequently come into close contact with bats can decrease any chances of spillback by adopting basic personal protective equipment and biosafety practices.

Animal Concerns Research and Education Society (Acres) deputy chief executive Kalai Vanan told The Straits Times that measures recommended by NParks, such as hanging CDs at entrance points, do help to deter bats.

But a long-term solution is to deny them roosting spots. He said Acres had often observed that bats prefer to hang from roughly textured ceiling areas, wooden decking and mesh, so if some of these features can be removed, bats will be more unlikely to return to roost.

Kalai reiterated that bats play a vital role in pollination, seed dispersal and insect population control. Anyone who spots an injured or stranded bat can call the 24-hour Acres hotline on 9783-7782 in Singapore or contact NParks.

He added: "We have seen people using DIY netting and mesh to deter bats as well, but we advise against these methods as we have seen many cases where the bats and other animals get stuck and entangled on the netting.

"Not only can they get injured and die a slow, painful death, but this ultimately puts these stressed animals even closer to you, which is not good." - The Straits Times/Asian News Network