Nearly 43,000 people may have gotten false negative Covid results in UK: Health officials

As the prevalence of Covid-19 infection seems to rise in England, British health officials said on Friday that nearly 43,000 people may have been given a false negative Covid-19 test result due to problems at a private laboratory.

The UK Health Security Agency said the Immensa Health Clinic Ltd. lab in Wolverhampton, central England, has been suspended from processing swabs after the false negatives.

Will Welfare, the agency's public health incident director, said it was working “to determine the laboratory technical issues” behind the inaccurate tests.

The issue was uncovered after some people who were positive for Covid-19 when they took rapid tests went on to show up as negative on more accurate PCR tests.

The health agency said 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,” mostly in southwest England.

The incorrect results were given between 8 September and 12 October.

The agency said it was “an isolated incident attributed to one laboratory” and people affected would be contacted and advised to get another test.

Immensa was awarded a 119 million-pound ($163 million) coronavirus-testing contract by the British government in October 2020. Chief executive Andrea Riposati said the company was “fully collaborating” with UK health authorities.

Alexander Edwards, an associate professor of Biomedical Technology at the University of Reading, said the problems were disappointing, but cautioned: “Let's not throw the baby out with the bathwater.”

“The majority of test results are correct, and it's worth remembering that our testing system has been built up from almost nothing at the start of the pandemic,” he said.

Britain conducts about 1 million coronavirus tests a day and reported almost 40,000 new infections a day over the past week.

Covid-19 cases rise

The prevalence of Covid-19 infections in England increased to around 1 in 60 people in the week ending 9 October, Britain's Office for National Statistics said on Friday, reaching its highest level since January.

The ONS said that prevalence of infections had risen for its third straight week, having been at 1 in 70 people in the previous week.

The rise takes prevalence to higher levels than were recorded in July, when infections spiked around the end of the Euro 2020 soccer championships, shortly before Prime Minister Boris Johnson fully reopened the economy.

Estimated prevalence was last higher in the week ending 23 January, shortly after England entered its third national lockdown.

However, Johnson has said that the widespread deployment of vaccines means that the link between cases and deaths has been disrupted. He has said that the government will rely on vaccines rather than lockdowns to navigate a difficult winter.