SINGAPORE - It now takes only 1.2 days to isolate linked cases in the community from the day they show symptoms, which is shorter than before, said Health Minister Ong Ye Kung on Friday (June 18).

He did not elaborate on how long it had taken previously.

Mr Ong noted that the 14-day moving average of the time taken to isolate these cases has been gradually coming down over the past few weeks.

A 14-day moving average looks at the average number of cases in the last 13 days, plus the current day, with this window period shifting continuously.

Speaking at the media conference of the multi-ministry task force tackling Covid-19 on Friday, Mr Ong said the improvement is important as it means the point of onset of symptoms for an infected person and the point at which he is isolated is now very close together, taking only 1.2 days.

This also means there is a smaller window in which that person can move around and transmit the virus to others, which also helps to lower the number of unlinked cases in the community.

He said that over the past seven days, 53 per cent of the cases were linked and already isolated, 28 per cent were linked but not isolated, while 19 per cent were unlinked.

Compared with the previous seven days, the percentage of unlinked numbers had remained stable at 19 per cent.

However, only 5 per cent were linked and not isolated then, while 76 per cent of the cases were linked and already isolated.

"The cases over the past few days are largely driven by the cluster at Bukit Merah View Market and Food Centre. Although it is largely an open-air area, there were still fairly widespread transmissions," said Mr Ong.

There were 94 locally transmitted cases over the past seven days, compared with 41 cases in the previous seven days, he added.