SINGAPORE - Seventeen recovered workers at Westlite Woodlands Dormitory have been found to be positive for Covid-19, said the Ministry of Health (MOH) on Thursday (April 22).

They were detected as part of special testing operations at the dorm after a 35-year-old Bangladeshi staying there was confirmed to have the coronavirus on Monday.

These cases were immediately isolated and taken to the National Centre for Infectious Diseases (NCID), said MOH.

The ministry, together with an expert panel which comprises infectious diseases and microbiology experts, is investigating if they are reinfection cases.

Apart from the cases in the dorm, MOH said there were 24 new coronavirus cases confirmed as at Thursday noon (April 22), taking Singapore's total to 60,904.

They include one community case and one new case from migrant workers' dormitories, it said.

The remaining cases were imported and placed on stay-home notice upon arrival in Singapore.

More details will be announced on Thursday night.

On Wednesday, the sole Covid-19 community case reported is a 39-year-old systems engineer at healthcare provider Parkway Pantai.

He has been working from home and has not returned to the workplace. He is asymptomatic and his case is currently unlinked, said MOH.

The permanent resident was in India from July 9 last year to Jan 24 this year.

On his return to Singapore, he served his stay-home notice at a dedicated facility until Feb 7.

He was negative for Covid-19 when tested then.

However, he tested positive on Monday when he took a pre-departure test prior to a trip, and was then taken to the National Centre for Infectious Diseases.

"His CT value was very high, which is indicative of a low viral load, and his serology test result has come back positive," said MOH.

"He could be shedding minute fragments of the virus RNA from a past infection which are no longer transmissible and infective to others, but given that we are not able to definitively conclude when he had been infected, we will take all the necessary public health actions as a precautionary measure," it added.

There were 14 other coronavirus cases confirmed, all imported, taking the tally to 15 cases reported on Wednesday.

The number of new cases in the community has increased from two cases two weeks ago to nine in the past week.

The number of unlinked cases in the community in a week has also increased from one case to five over the same period.

With 36 cases discharged on Wednesday, 60,561 patients have fully recovered from the disease.

A total of 70 patients remain in hospital, including one in critical condition in the intensive care unit, while 204 are recuperating in community facilities.

Singapore has had 30 deaths from Covid-19 complications, while 15 who tested positive have died of other causes.

Globally, the virus outbreak, which began in December 2019, has infected more than 143 million people. Over 3.05 million people have died.