Testing of patients with influenza-like symptoms during visits to general practitioner (GP) clinics and polyclinics in Singapore has turned up 13 Covid-19 cases over three months.
This “random testing” in the community complements other Covid-19 screening programmes, Health Minister Gan Kim Yong said on March 21.
He added that “a few cases” have been detected this way.
“The idea is to pick up cases that otherwise would not have not been detected,” he said then.
What determines during random testing
Samples collected from patients with symptoms, such as fever and cough for common respiratory viruses, including influenza viruses, are routinely tested.
Some of the cases show symptoms that are mild or do not fit the criteria to be treated as a Covid-19 suspect case.
About 300 to 600 samples are tested monthly for common respiratory viruses, including influenza viruses, the Ministry of Health (MOH) said.
MOH said this sentinel surveillance programme has been ongoing since 2007.
Since Jan. 26, three days after Singapore confirmed its first imported case of the virus, these samples were also tested for Covid-19.
Around 1,200 samples have been tested for Covid-19 as of April 28.
A total of 13 cases subsequently tested positive for the coronavirus.
As a result of these random tests, MOH said: "There is no evidence of widespread community transmission. Contact tracing is carried out for all confirmed cases."
This has become one of the ways the spread of Covid-19 in the community is monitored.
Active detection by doctors
Active detection of Covid-19 cases is also carried out by front line doctors.
All patients with prolonged acute respiratory infection are tested by the polyclinics and more than 200 GP clinics.
Such a method of detection is to facilitate active case finding of Covid-19 infection in the community.
As of April 28, close to 5,800 swabs have been performed on such patients, who have fever of 37.5°C or more, and whose symptoms persist for at least four days.
Of these, more than 130 cases tested positive for Covid-19.
Small proportion of overall tests done
Some 7,000 tests have been conducted via the sentinel surveillance programme and testing done by front line doctors.
But this figure is just a tiny proportion of tests conducted in Singapore.
An estimated 144,000 tests have been conducted here as of April 27.
Singapore has done about 25,200 swabs per million people, MOH’s website said.
A large number of these have been conducted in the migrant worker community.
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