After last month's discovery of an infection cluster at Bukit Panjang's transport centre, around 11,000 people working in public bus depots and interchanges will now be screened for Covid-19.
These include all bus drivers as well as employees such as administrative staff.
The authorities said this was an added precautionary measure after active case finding uncovered evidence of nearly 100 past infections among people linked to the Bukit Panjang cluster. The idea is to detect and ring-fence cases as early as possible, and prevent large clusters from forming.
"Where infection clusters form, we will promptly quarantine and test close contacts, mount swab operations, and suspend operations at the relevant facility if deemed necessary," said the Ministry of Health (MOH) and Land Transport Authority (LTA) yesterday.
But the authorities stressed that the risk to commuters is low, since contact on public transport is transient, with drivers and passengers all wearing masks.
Sharing this view, Professor Teo Yik Ying, dean of the National University of Singapore's Saw Swee Hock School of Public Health, said the risk of workplace transmission of the virus is higher.
"It's likely that bus drivers will be having meals together or chatting with each other during breaks. Those are the kind of interactions where they may not have their masks on and they will be in closer proximity," he told The Sunday Times.
Last month, a new cluster comprising several bus drivers and interchange staff emerged at Bukit Panjang Integrated Transport Hub.
After the first three cases were detected, swab operations were carried out at seven locations between July 23 and Aug 5. They included two bus depots and two places of accommodation, with more than 3,700 people tested so far.
Public transport workers and contractors who had been in close contact with confirmed cases were tested, as were all staff at the transport hub and those at workplaces and accommodation where confirmed cases had been.
The tests showed that six people either had active infections or past infections, while another 89 were found to have recovered from past infections and were no longer infectious. "Of these (89) individuals, 12 had previously been living in the dormitories," the authorities said.
"As an added precautionary measure, we will also be working with LTA to conduct PCR tests for the rest of the staff in the public bus industry who work at depots and interchanges." Polymerase chain reaction tests are used to uncover active infections, although they can also be indicative of past infections.
The screening of the 11,000 staff will be done over the next nine days.
Public transport operators have strict hygiene and safe management measures in place, and commuters should do their part, which includes keeping their masks on and not talking on the bus or train, MOH and LTA said.
The cluster at Bukit Panjang is believed to be the first to have emerged in the community since the circuit breaker ended on June 1.
Several bus drivers approached by The Straits Times on Friday confirmed that they and their colleagues had already been swabbed and had their blood drawn for testing.
"The swab test was nothing," said one driver, who declined to be named. "It wasn't painful, it was only a bit ticklish."