75 unlinked Covid-19 cases in S'pore in past 2 weeks raising concerns

Before this month’s spike, there were 68 unlinked cases reported from the start of year.

Unlinked cases are a concern because they suggest the presence of undetected reservoirs of infections in the community.
Unlinked cases are a concern because they suggest the presence of undetected reservoirs of infections in the community. ST PHOTO: YONG LI XUAN

SINGAPORE - The number of unlinked Covid-19 cases in Singapore has been going up steadily this month, giving rise to concerns that there are undetected reservoirs of infections in the community. 

There were 75 unlinked local Covid-19 cases reported from May 7 to May 20 (Thursday), compared with the total of 68 unlinked cases reported from the start of the year, before the spike.

On May 14, Mr Lawrence Wong, co-chair of the multi-ministry task force tackling Covid-19, cited the rise in unlinked cases when announcing tightened restrictions such as capping the size of gatherings and number of visitors per household at two people, and making work-from-home arrangements the norm.

The average daily number of unlinked cases was trending downwards at the start of this year. In January, there were about 0.58 unlinked cases per day, falling to 0.46 in February and 0.26 in March.

But the average number of unlinked cases last month rose to 0.7 per day. It then climbed to 4.15 cases per day from May 1 to May 20.

This trend, and the rise in overall cases and clusters amid a more transmissible Covid-19 variant, has some speculating that Singapore is headed for another circuit breaker. The authorities have said that while the possibility of further tightening remains, such a move is not set in stone.

Mr Wong, the Finance Minister, said at the May 18 task force press conference that the rise in unlinked cases this month does not mean that measures are not working.

"In fact, I have confidence that the latest measures that we have put in place to restrict interactions and movement will have an impact in bringing numbers down. But we will only see this materialising one to two weeks later because of the time lag in these measures," he said, noting that the cases currently being detected were likely infected one or two weeks ago.

The average daily number of unlinked cases from March 4 to April 3 last year, when the circuit breaker was announced, was 6.42.

There were 15 active clusters then.

From April 20 to May 20 this year, the average daily number of unlinked cases was three. There are currently 24 active clusters.

In a recent message that was widely shared, Associate Professor David Lye of the National Centre for Infectious Diseases (NCID) called on people to mask up properly, avoid crowded places and big groups, get vaccinated, and not socialise beyond a small social bubble.

There are also the basics to remember: cleaning hands with soap and water, or a sanitiser; not touching the face; and seeing a doctor without delay when unwell.

These steps, coupled with measures the authorities are taking, will be crucial in keeping infection numbers from spiking even further, he said.