About 43,000 people ‘wrongly given negative PCR Covid-19 test result’

An estimated 43,000 people are believed to have been wrongly given a negative PCR Covid-19 test results, the UK Health Security Agency (UKHSA) has said.

Operations provided by Immensa Health Clinic Ltd at a laboratory in Wolverhampton have been suspended by NHS Test and Trace following an investigation into why many people were reporting negative PCR test results following a positive result from a lateral flow test.

The negative PCR test results - which were given to people between September 8 and October 12 - means many people who had Covid-19 would have thought they did not, and would not have been required to isolate. They could potentially gave spread the virus to many more people, potentially contributing to the very high numbers of positive tests seen in recent days.

Health authorities said the test results will primarily have affected people in the South West of England, with some cases in the South East and Wales. The Cambridge Independent is aware, however, of a case in South Cambridgeshire in which an individual in a household with Covid-19 had tested positive on a lateral flow test, but then negative on a PCR test.

Asked if Cambridgeshire labs had sent samples to the Immensa laboratory, a spokesperson for UKHSA said: “We don’t have specific information on whether any Cambridgeshire labs have provided samples to the lab in Wolverhampton. If anyone in our region should be affected by the situation, NHS Test & Trace 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.”

UKHSA, which replaced Public Health England, said there was nothing wrong with the test kits themselves and people should continue to test as normal.

A full investigation into how it happened is being carried out.

UKHSA chief executive Dr Jenny Harries told the BBC it was likely only a few thousand of the 43,000 affected were still infectious.

Dr Harries said it was “not clear yet” what went wrong in the private laboratory, which was “accredited to all of the appropriate standards”.

About 400,000 samples have been processed through the lab, but now new samples are now sent elsewhere.

The sudden rise in people reporting positive lateral flow tests followed by negative PCR tests had been the source of confusion.

If a person has a positive lateral flow result, they are told to have a follow-up PCR to confirm the finding.

PCR tests are considered the gold standard of tests and can detect Covid-19 several weeks after infection.

This week, a new study from UCL, Liverpool University, Harvard University and the University of Bath showed lateral flow tests - when used correctly - are much more accurate than initially thought.

Researchers published a peer-reviewed paper on Thursday (October 14) in Clinical Epidemiology that used a new formula to show that lateral flow tests (LFTs) are likely more than 80 per cent effective at detecting any level of Covid-19 infection and likely more than 90 per cent effective at detecting those who are most infectious when using the test.

Dr Will Welfare, public health incident director at UKHSA, said: “We have recently seen a rising number of positive LFD (lateral flow) 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.”

Tim Barton, 48, told the PA news agency he and his family received positive lateral flow tests after falling ill with coronavirus symptoms earlier this month but their PCR tests came back negative.

The client relationship director said: “My son, daughter and myself all had positive (lateral flow tests) – we then had PCR tests done at the test site in Swindon all of which came back negative.

“This will undoubtedly impact people’s confidence in the accuracy of these types of tests… they could have cost lives.”

The government awarded Immensa a £119million contract in October 2020 to urgently “develop volume for PCR testing for Covid in line with test and trace requirements”, the contract shows.

The contract did not go to tender under rules allowing urgent responses to the pandemic.

A further £50million was awarded to Immensa by the government in a contract last September.

Andrea Riposati, chief executive of Immensa, said: “We are fully collaborating with UKHSA on this matter. Quality is paramount for us. We have proudly analysed more than 2.5 million samples for NHS Test and Trace, working closely with the great teams at the Department for Health and UKHSA.

“We do not wish this matter or anything else to tarnish the amazing work done by the UK in this pandemic.”

Immensa was incorporated as a company in the UK in May 2020.

Additional reporting: PA

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