SINGAPORE - The Health Ministry (MOH) said on Sunday (May 10) that 33 Covid-19 cases from a laboratory were false positives, due to an apparatus calibration issue for one of its test kits.
Subsequent retesting at the National Public Health Laboratory confirmed that the cases, and two more that had equivocal results, were actually negative.
MOH said no false negative results were discovered and immediate action has been taken to rectify the situation. The lab has also stopped all tests and is working to solve the calibration issue.
There was also one imported case among the 876 new cases confirmed, which brings the total Covid-19 case count in Singapore to 23,336. He is a 61-year-old Singaporean man with a travel history to Qatar who was placed on stay-home notice upon arriving in Singapore.
This is the first imported case in over two weeks since two imported cases were confirmed on April 26.
Work permit holders residing in dormitories made up 860 of the new cases. There were 11 cases of work permit holders outside dormitories.
A total of 20,961 workers from dormitories have been diagnosed with Covid-19 so far, accounting for about 6.5 per cent of 323,000 dorm residents.
MOH also identified five new clusters on Sunday. They are: construction sites in 15 Serangoon North Avenue 1 and Tanah Merah Coast Road, 9 and 11 Woodlands Industrial Park E1, and 515 Yishun Industrial Park A.
A cluster at a construction site in 6 Battery Road has been closed as there were no new links for 28 days, or two incubation periods.
Of the new cases, 98 per cent are linked to known clusters, with the rest pending contract tracing.
Three new cases were Singaporeans and permanent residents. One was linked to the Mustafa Centre cluster, while another was linked to Acacia Home at 30 Admiralty Street.
Another 425 patients have been discharged from hospitals or community isolation facilities and fully recovered. In all, 2,715 have fully recovered and been discharged.
There are 1,097 who are still in hospital, with 22 in the intensive care unit.
The remaining 19,498 are at community isolation facilities, which house Covid-19 patients who have mild symptoms or are clinically well but still tested positive.
So far, 20 people have died from Covid-19 complications here and six others who tested positive have died from other causes.
Local cases excluding dormitory residents and other work permit holders fell to an average of nine daily the past week, from 11 two weeks ago.
The number of such cases that were unlinked has also dipped to an average of four a day from five, over the same period.
Singapore now has the highest number of confirmed coronavirus cases in South-east Asia. The Republic took 13 weeks from the first reported case on Jan 23 to cross 10,000 cases on April 22 but just two weeks to reach 20,000 cases on Wednesday.
The spike is largely driven by a rise in cases of migrant workers living in dormitories, which the authorities have said remain high due to extensive testing.