SINGAPORE, Dec 21 — Three people who served stay-home notices (SHN) at Mandarin Orchard Singapore have tested positive for Covid-19, but these are likely to be imported cases.

The Ministry of Health (MOH) said this yesterday as it gave an update on its investigations into the 13 infections among people who served SHN at Mandarin Orchard Singapore.

In total, 394 people serving SHN at the hotel have been swabbed. Out of 384 test results that are ready, 381 have come back negative.

The three who tested positive were immediately conveyed to the hospital via ambulance, MOH said.

"As they have recent travel history, it is likely that these are imported and have been included in today’s case count,” the ministry added. MOH reported 19 new cases of Covid-19 yesterday, all of which were imported.

The National Public Health Laboratory will conduct whole genome sequencing and phylogenetic analysis to determine if the trio could be linked to the 13 cases, MOH said.

The ministry has also tested 571 staff of Mandarin Orchard Singapore.

Of these, 158 test results have been processed, while 413 results are pending.

All 158 polymerase chain reaction test results have come back negative.

However, the serological tests of three staff have come back positive, indicating likely past infections. — TODAY