SARS-CoV-2 testing issues at a UK lab should have been caught faster, scientists tell the Guardian.
Earlier this month, officials suspended SARS-CoV-2 testing at Immensa Health Clinic's Wolverhampton location, following reports that a number of people tested positive for SARS-CoV-2 via lateral flow testing but then were negative by PCR analysis. According to GenomeWeb, the NHS Test and Trace program estimated that about 43,000 people received an incorrect negative PCR test result between Sept. 8 and Oct. 12.
The Guardian notes that neither Immensa nor the UK Health Security Agency noticed the discrepancies until academics and members of the public pointed them out. "You shouldn't be relying on anecdotal reports to spot a problem of this size," the University of Birmingham's Alan McNally tells the Guardian.
McNally adds there that PCR machines typically have controls that should alert those running the tests of failures and that labs should also check the data manually to spot, for instance, long stretches without any positive results.
"What is really surprising to me is that a problem like this was not picked up in the lab almost on the day," University College London's Deenan Pillay also tells the Guardian. "If anything looks strange, even if the number of positive tests goes down, then that is a clear red flag."