A total of 33 cases from a laboratory have been found to be false positives, the Ministry of Health said in its Covid-19 update for May 10.

They are cases 20844, 20847, 20850, 20853, 20854, 20855, 20856, 20973, 21018, 21021, 21024, 21111, 21120, 21163, 21166, 21170, 21370, 21456, 21581, 21595, 21596, 21598, 21599, 21600, 21601, 21602, 21603, 21604, 21605, 21606, 21607, 21608 and 21609.

MOH stated that the false positives were the result of an apparatus calibration issue for one of the laboratory's test kits.

These 33 cases were subsequently confirmed to be negative upon re-testing at the National Public Health Laboratory.

MOH has since taken immediate steps to address the situation.

No false negatives found

No other false negatives have been found from MOH's review of the matter.

In the meantime, the laboratory in question has stopped all tests and is working to resolve the calibration issue.

Two results found to be equivocal

In addition, two results were also found to be equivocal.

They were confirmed as negative upon subsequent re-testing at the National Public Health Laboratory.

The cases in question are 18669 and 19360.

As a precautionary measure, MOH had categorised them as positive and isolated the two cases while the verification of their results were pending.

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