SINGAPORE: Singapore has had to lower its COVID-19 testing capacity over the past few days due to an issue at one of the laboratories which resulted in 33 "false positive" cases.
The Ministry of Health (MOH) had said that there was an "apparatus calibration issue" with one of the labs' test kits.
These "false positive" cases were discovered as a result of a quality assurance programme put in place to check on test results, said MOH's director of medical services Kenneth Mak on Tuesday (May 12).
Authorities are giving the lab time to properly recalibrate and revalidate its test kits as well as work through its "quality assurance processes", Assoc Prof Mak said.
“We lowered our testing capacity accordingly to give them some space to work through these processes. We anticipate that this should complete, very quickly, and we should be able subsequently to return back to our current full test capacity. This may take place over the next few days,” he added.
Singapore was conducting conducting between 7,500 and 7,600 COVID-19 tests a day before the issue at the laboratory was detected, said Assoc Prof Mak.
"The results that came out from that particular set of tests done were not interpreted correctly," he added.
"There were also some steps that had not been completed followed through. If those steps had been completely followed through, we might have perhaps picked some of these results a little bit earlier.
"We're working with the laboratory to complete this quality assurance process."
To avoid having incorrect results in future, MOH has put together advisories and guidance for all the laboratories involved in testing.
These advisories describe standard processes that they have to conduct to ensure that tests are performed correctly and that accurate tests are produced, said Assoc Prof Mak.
While tests could show up clearly negative or positive, there are situations where results are a "presumptive positive" based on the test process, he explained.
“There may be a need in those settings for complementary tests to be done. And we require the laboratories to perform all the confirmatory tests before the results are released, so that we have greater confidence in the test results being accurate,” he said.
“And these are some of the processes that are currently being put in place as part of the quality assurance for all the local laboratories, and this would allow us to have continued confidence that the testing is done properly, and the results coming up from the test are correct as well."
The affected laboratory has also enlisted the support of its machine and test kit vendors to ensure that its tests are properly done, he added.
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SINGAPORE’S STRATEGY DOES NOT INVOLVE HERD IMMUNITY
In response to a question on herd immunity, Assoc Prof Mak said it is not part of Singapore's strategy to attain herd immunity through the natural spread of the virus.
“It is too big a price for us to pay," he told reporters.
"If we assume that we're going to let COVID-19 spread freely in our population, we will then have to accept the cost associated with more seniors getting ill, more seniors getting complications and a number of seniors even dying from infection."
He added that hospitals would also be overwhelmed in such a situation.
“This is a situation which is a very dangerous one because it may see us in the situation where, very easily, the sheer numbers of people who are getting sick and infected overwhelm the resources that we have, even though we've taken many steps to prepare for surges, to expand our capacity,” he said.
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Assoc Prof Mak noted that other countries like the United Kingdom have tried the herd immunity strategy, but eventually moved on to other methods to stem the spread of COVID-19 because the “cost was too big, too painful for them to bear”.
Sweden, which has also used the strategy, has seen high mortality rates, he noted.
“With good containment, we will never reach a situation where herd immunity is achieved unless vaccination takes place, and it's important for us to understand this,” Assoc Prof Mak said.