UKHSA publishes investigation findings following errors at the private Immensa lab
The UK Health Security Agency (UKHSA) has published findings of an investigation following errors at the private Immensa laboratory in Wolverhampton.
The laboratory was commissioned to provide additional testing capacity for NHS Test and Trace from 2 September 2021. UKHSA suspended testing at the laboratory on 12 October 2021 following reports of inaccurate results.
The cause was the incorrect setting of the threshold levels for reporting positive and negative results of PCR samples for coronavirus (COVID-19) by staff in Immensa’s Wolverhampton laboratory. This means that some PCR tests were reported by the lab as negative for COVID-19 which would have been assessed as positive if the threshold had been correctly set.
Based on background infection rates in different population groups at the time, UKHSA estimated that this error could have led to around 39,000 results being incorrectly reported as negative when they should have been positive. This represents around 10% of samples tested at the laboratory between 2 September and 12 October 2021 and 0.3% of all samples tested for NHS Test and Trace during this period.
In addition, UKHSA researchers have also published an analysis to estimate the impact of the Immensa lab error on transmission in the most affected areas.
UKHSA’s serious incident investigation has concluded that no singular action or process implemented by NHS Test and Trace could have prevented the errors within the Immensa laboratory arising, but it has also identified a range of ways to enable earlier detection of any similar laboratory errors wherever possible.
NHS Test and Trace acted immediately to strengthen its contract and data processes when the issue first emerged and a summary of these actions has also been published alongside the serious incident investigation. These include enhanced surveillance of laboratory positivity rates so that discrepancies can be identified and investigated as soon as possible.
Richard Gleave, UKHSA director and lead investigator, said:
Through this investigation we have looked carefully at the arrangements in place for overseeing contracts of private labs providing surge testing during this time. We have concluded that staff errors within Immensa’s Wolverhampton laboratory were the immediate cause of the incorrect reporting of COVID-19 PCR test results in September and October 2021.
It is our view that there was no single action that NHS Test and Trace could have taken differently to prevent this error arising in the private laboratory. However, our report sets out clear recommendations to both reduce the risk of incidents like this happening again and ensure that concerns are addressed and investigated rapidly.
Jenny Harries, UKHSA Chief Executive, said:
UKHSA is committed to being a transparent, learning organisation and this means investigating where things have gone wrong and working out how things can be improved.
I fully accept the findings and recommendations made in this report, many of which were implemented as soon as UKHSA discovered the incident. These ongoing improvements will enhance our ability to spot problems sooner where they do arise.
We are particularly keen to further improve how we work with local partners and directors of public health as rapid incidents like this unfold.
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