Pilot test in Q1 to allow migrant workers in some dorms to access community

MIGRANT workers in some dormitories will be allowed to access the community once a month as part of a pilot scheme to be kicked off in Q1 next year, subject to compliance with rostered routine testing (RRT), wearing of contact tracing tokens, and safe living measures, said the Ministry of Health (MOH) on Monday.

The government is in the midst of distributing contact-tracing devices to more than 450,000 workers living in dormitories or working in the construction, marine and process sectors, and are on track to completing distribution of these tokens by end-December.

This is in addition to the building of new dormitories with improved safety standards to minimise the risk of resurgence of Covid-19 among migrant workers.

Meanwhile, the government is also continuing its multi-layered strategy of aggressive routine testing using both Polymerase Chain Reaction (PCR) tests and antigen rapid testing, accompanied by isolation strategies.

As at Dec 13, 54,505 dormitory residents have tested positive using the PCR test. This is out of a total of over 320,000 migrant workers who live in dormitories. At the peak of the outbreak in April, more than 1,000 new cases a day were being detected in the dormitories. There were 25 Covid-19-related ICU admissions and two deaths.

By August, all migrant workers have been tested at least once for Covid-19. By early November, more than 98 per cent living in dormitories were cleared to resume work.

Meanwhile, another 98,289 have tested serology-positive though they did not have a positive PCR test. People who have been tested serology-positive had been infected earlier. These workers underwent a seven-day period of isolation, at the end of which they were deemed to be no longer infectious and did not need to be tested further.

The Ministry of Manpower (MOM) and MOH noted that they are still in the process of completing serology tests for 65,000 or so migrant workers living in dormitories who had not taken a serology test before. This will provide a full picture of the infection prevalence among the migrant workers.

"As these tests identify past cases of infection, they are used to aid epidemiological investigations and for retrospective assessment of the overall prevalence of infections within a population," said MOM and MOH in a statement. While most countries only conduct serology testing on a sampling basis, Singapore went further to do serology tests on the entire population of migrant workers living in dormitories.

Including the serology test results, the prevalence rate of Covid-19 in the dormitories is currently 47 per cent. For every Covid-19 infection in the dormitories detected through PCR testing, another 1.8 cases were untested and undetected at the time, and were identified subsequently only through serology testing.

The government noted that this is not surprising as many migrant workers did not have symptoms and thus would not have sought treatment and received a PCR test in the process. Among migrant workers who tested PCR-positive or serology-positive, only one in five migrant workers living in purpose-built dormitories presented with symptoms while four in five displayed very mild or no symptoms.

The ratio of PCR-positive to serology-positive among migrant workers in dormitories is comparable to the ratio of 1:1.8 for the whole of South Korea, and lower than 1:4 in Spain, and 1:15 in France.

The government is also monitoring the earliest cohort of migrant workers who have recovered from Covid-19 and are currently exempt from RRT.

"We are studying how their antibodies change over time. We will resume RRT for these workers if we detect their antibodies starting to fade, or if there is evidence of re-infection among them," said MOH.