Testing operations by the Immensa Health Clinic, Wolverhampton, have been suspended following an investigation into reports of people receiving negative PCR test results after they have previously tested positive on a Lateral Flow Device (LFD).
While investigations are underway into the precise cause, NHS Test and Trace (NHS TT) estimate that around 400,000 samples have been processed through the lab, the vast majority of which will have been negative results, but an estimated 43,000 people may have been given incorrect negative PCR test results between 8 September and 12 October, mostly in the South West of England.
NHS TT is contacting the people that could still be infectious to advise them to take another test. Close contacts who are symptomatic will also be advised to take a test in line with normal practice.
Dr Will Welfare, Public Health Incident Director, UK Health Security Agency (UKHSA), said: "We have recently seen a rising number of positive LFD results subsequently testing negative on PCR. As a result of our investigation, we are working with NHS Test and Trace and the company to determine the laboratory technical issues which have led to inaccurate PCR results being issued to people. We have immediately suspended testing at this laboratory while we continue the investigation.
"There is no evidence of any faults with LFD or PCR test kits themselves and the public should remain confident in using them and in other laboratory services currently provided."