SINGAPORE - There were five new coronavirus cases confirmed as at Monday noon (Dec 28), taking Singapore's total to 58,529.

There were four imported cases who were placed on stay-home notice or isolated on arrival in Singapore, said the Ministry of Health (MOH).

There was one new community case and none from worker dormitories.

On Sunday, five new coronavirus cases were reported. All of them were imported.

Among the five, a 23-year-old female work permit holder had served a stay-home notice at Mandarin Orchard Singapore before she was transferred to another dedicated facility on Dec 20.

On that day, MOH commenced investigations into 13 previously reported cases who had served stay-home notices at the hotel between Oct 22 and Nov 11.

The 13 cases, which came from 10 different countries, were infected by coronavirus strains with "high genetic similarity", which implied that the infections might have come from one source and could have happened in the hotel.

The Malaysian, identified on Sunday night as Case 58,762, was swabbed on Dec 19 and Dec 21 and her test results were negative for Covid-19 infection.

Her swab last Thursday at the end of her stay-home notice came back positive, and she was taken to the hospital the next day.

A confirmatory test by the National Public Health Laboratory (NPHL) was also positive.

However, a second sample taken by NPHL last Saturday returned negative, and her serological test result has also come back negative, said MOH.

The latter test determines if the infection was an old one.

Investigations are being done to determine if she could be linked to the 13 cases being investigated by MOH.

She was the third Covid-19 patient who tested positive for the virus after serving part of a stay-home notice at Mandarin Orchard Singapore. The two other cases were announced last Friday and Saturday.

Among the four other imported cases on Sunday, one is a permanent resident. The 33-year-old man returned from Ukraine.

The remaining three are foreign domestic workers holding work permits.

They included two Indonesians aged 37 and 38, and a 48-year-old Filipino woman.

All five patients had all already been placed on stay-home notice on arrival in Singapore and were tested while serving their notices.

Singapore has had 29 deaths from Covid-19 complications, while 15 who tested positive have died of other causes.

Globally, the virus outbreak, which began in December last year, has infected more than 80.7 million people. More than 1.76 million people have died.