The increasing number of detected Covid-19 cases with low viral load is not due to the coronavirus mutating but, rather, a result of Singapore's unique testing strategy, said the Ministry of Health's (MOH) director of medical services Kenneth Mak yesterday.
Last Wednesday, the ministry announced that six students and staff who had tested positive for the disease earlier in the month had displayed mild symptoms and had low viral loads.
Speaking at a virtual press conference yesterday, Associate Professor Mak pointed out that Singapore has been expanding its testing strategies, leading to a larger pool of asymptomatic people being tested.
"As we test more, it is inevitable that we will find more people who have had infections in the past and who remain asymptomatic. And it is not surprising that their onset of illness could have been some time ago. That partially accounts for why their viral loads are low at the time when they actually are diagnosed," he said.
"It doesn't necessarily reflect that the virus has changed in any way."
Health Minister Gan Kim Yong, who was also at the press conference, said that the Republic's "aggressive" method of testing means that its data cannot be compared with that of other countries, which may have a different basis for testing people.
He added that because cases with low viral load are usually asymptomatic, they tend to feel that there is nothing wrong with them and do not seek medical attention.
As a result, they would not have been detected under "normal circumstances".
Prof Mak also clarified that mutations are a common occurrence in all viruses, not just the one which causes Covid-19.
"We see mutations in the virus causing Covid-19 infection, but that doesn't necessarily imply that mutation variants or strains are more infectious or cause more harm," he said.
He added that the authorities are not aware of any evidence suggesting that the recent mutations of the coronavirus have made it deadlier.
Nevertheless, they will continue to review all available evidence and research, and monitor the situation carefully.
"We look towards our scientific experts to provide us with guidance and advice as to what we should do if we're dealing with virus strains that in fact lead to a change in behaviour of the virus. But so far there's no evidence to suggest (this)," said Prof Mak.
