More than 225,000 Covid-19 self-test kits have been distributed to residents and visitors who visited markets and food centres linked to the Jurong Fishery Port cluster.
In response to queries from The Straits Times, the Ministry of Health (MOH) said it worked with the People's Association to distribute these antigen rapid test (ART) kits between July 20 and 25.
The kits were given to those who had visited places such as Chong Boon Market and Food Centre and Whampoa Drive Wet Market, said MOH on Tuesday. The two markets have several Covid-19 cases linked to them.
As at yesterday, there were 932 cases linked to the Jurong Fishery Port and Hong Lim Market and Food Centre cluster.
Antigen rapid tests involve inserting a swab stick approximately 2cm into the nostril, but instructions and requirements vary depending on the brand of test kit used.
In general, antigen rapid tests can achieve sensitivity of about 80 per cent for cases with higher viral loads and a specificity range of 97 per cent to 100 per cent, said MOH.
Sensitivity refers to a test's ability to identify those infected as positive, while specificity refers to a test's ability to correctly identify those not infected as negative.
Anyone whose self-test is positive or returns an invalid result twice should take a photo of the test next to their identity card or passport before disposing of the kit.
They should then follow up with a confirmatory polymerase chain reaction (PCR) test at a Swab and Send Home clinic. Clinics can be found at the Flu Go Where website.
All households will receive Covid-19 self-test kits progressively, as Singapore scales up its testing regime and works to live with the coronavirus.
Experts told The Straits Times that these self-test kits will play a significant role in Singapore's Covid-19 strategy, making it easier for people to get tested faster.
Associate Professor Alex Cook, vice-dean of research at the Saw Swee Hock School of Public Health at the National University of Singapore, said: "What makes ART so useful is that the results come out much faster than in a PCR test, and it can be done easily at home or at a work site. (This) makes it much easier for those who think they don't have Covid-19 infection, but aren't sure, to quickly confirm their suspicions."
Professor Teo Yik Ying, the dean of the school, said the distribution of the antigen rapid test kits provides Singapore residents with an opportunity to learn how to use them.
"Moving forward, Singapore may cease its contact tracing activities, and that means individuals who may be exposed and infected may not even be aware themselves, especially when they are fully vaccinated and do not have any symptoms upon infection."
The ART kits can hence provide peace of mind to those who suspect they are infected, he said.
But infectious disease experts pointed to a possible issue: Some people, upon getting a positive ART result, may not see a doctor as they fear being inconvenienced by a positive Covid-19 diagnosis, especially if they do not feel ill.
Dr Leong Hoe Nam, an infectious disease specialist from Rophi Clinic, noted how the fear of being quarantined and being away from comfort may deter those who are ART-positive from taking a confirmatory PCR test.
He urged the public not to avoid taking action, stressing that Singapore has to bear a high cost, financial or otherwise, if Covid-19 cases continue rising.
"This includes quarantine, hospital stays and being admitted into intensive care. In addition, getting admitted deprives another individual with a valid medical illness of hospital care," he said.
"Antigen rapid tests are effective, conserve precious resources and save lives."
