SINGAPORE - Serological tests of eight more hotel employees at Mandarin Orchard Singapore have come back positive, indicating likely past infections of Covid-19, said the Ministry of Health (MOH) on Monday afternoon (Dec 21).
This is in addition to the three cases announced on Sunday. Epidemiological investigations of these 11 cases are in progress, said the ministry.
In the meantime, the MOH is testing their identified close contacts as a precautionary measure, and it will also conduct serological tests to determine if these individuals could have been infected by these 11 cases.
The 11 cases were excluded from the Covid-19 daily counts reported by the health ministry, as their polymerase chain reaction (PCR) test results are negative for the infection, indicating that these are likely to be past, and not current, infections.
The MOH said: "Singapore reports Covid-19 cases in accordance with international practice. Every case who tested positive through a PCR test and is assessed to be an acute infection is reported and included in our case count. We follow the World Health Organisation's criterion that only positive results from confirmatory tests (that is, PCR tests) are included in the case count."
In total, MOH has tested 571 staff of Mandarin Orchard Singapore, and all the Polymerase Chain Reaction (PCR) test results have come back negative for Covid-19 infection. This means there is no ongoing infection among staff of the hotel.
In total, 394 people serving stay-home notice (SHN) at the hotel have been swabbed. Of these, three tested positive on Sunday and were immediately conveyed to the hospital via ambulance.
These cases were included in the ministry's daily case count on Sunday.
As they have recent travel history, it is likely that these are imported cases who were infected while they were overseas, said the MOH.
However, the National Public Health Laboratory will conduct whole genome sequencing and phylogenetic analysis to determine if they could be linked to the 13 cases.
As a precautionary measure, all existing guests at the hotel were checked out by 9pm on Sunday.
Those serving SHN there were transported by dedicated vehicles to an alternative SHN dedicated facility on the same day, said the MOH.