UK Health Security Agency News and Media

15 Oct 2021

Testing at private lab suspended following NHS Test and Trace investigation

  • Following reports of people receiving negative PCR test results after they have tested positive on a Lateral Flow Device, NHS Test and Trace has investigated and testing has been suspended at a private laboratory
  • There are no technical issues with the LFD or PCR test kits themselves and people should continue to test as normal. Other labs are working normally
  • Anyone with COVID-19 symptoms should book a PCR test. Those with a positive LFD test should get a follow up PCR test to confirm they have COVID-19.

NHS Test and Trace (NHS TT) have suspended testing operations provided by Immensa Health Clinic Ltd at its laboratory in Wolverhampton, following an investigation into reports of people receiving negative PCR test results after they have previously tested positive on a Lateral Flow Device.

While investigations are underway into the precise cause, NHS Test and Trace 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.

This is an isolated incident attributed to one laboratory but all samples are now being redirected to other laboratories. The number of tests carried out at the Immensa laboratory are small in the context of the wider network and testing availability is unaffected around the country.

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.  Anyone with COVID-19 symptoms should book a PCR test. Those with a positive LFD test should get a follow up PCR test to confirm they have COVID-19.

Dr Will Welfare, Public Health Incident Director, UKHSA: 

“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. If you get a positive LFD test, it’s important to make sure that you then get a follow up PCR test to confirm you have COVID-19. If you have symptoms of COVID-19, self-isolate and take a PCR test.”

Andrea Riposati, CEO of Immensa Health Clinic Ltd:

"We are fully collaborating with UKHSA on this matter. Quality is paramount for us. We have proudly analyzed more than 2.5M samples for NHS Test and Trace, working closely with the great teams at DHSC and UKHSA. We do not wish this matter or anything else to tarnish the amazing work done by the UK in this pandemic."

Contact Information

Luke Guinness
luke.guinness@phe.gov.uk

Notes to editors

For further information, please contact 020 7654 8400 or UKHSA-pressoffice@phe.gov.uk.

  • While the majority of people affected are in the South West, some in the South East of England and Wales are also affected
  • NHS Test and Trace currently carries out around 800,000 PCR tests each day.
  • PCRs have a specificity of 99.68% (that is, a false-positive rate of 0.32%), an overall sensitivity of 76.8%, and a sensitivity of over 95% for those with high viral loads.
  • If you get a positive LFD test it’s important to make sure that you then get a follow up PCR test to confirm you have COVID-19. If you have COVID-19 symptoms then you should get a PCR test immediately.
  • There is no evidence of emergence of new variants
  • All variants have been tested against the LFDs in use and LFDs continue to work at the expected standards set out on gov.uk