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Covid-19: PCR testing is suspended at private laboratory after high rate of false negatives

BMJ 2021; 375 doi: (Published 15 October 2021) Cite this as: BMJ 2021;375:n2535
  1. Ingrid Torjesen
  1. London

Testing for covid-19 has been suspended at a private laboratory in Wolverhampton after an investigation by the UK Health Security Agency into media reports of a spike in the number of people receiving negative PCR test results after they had tested positive for covid-19 on a lateral flow device (LFD).

The increase has been seen over several weeks, raising questions over why the laboratory’s quality control processes and those of NHS Test and Trace did not pick up the problem earlier. There are also questions concerning how many people who underwent PCR testing without an LFD result, such as contacts of people with positive cases and travellers returning from overseas, might also have been given negative results when they were actually infected.

Data from the Health Security Agency show that the proportion of negative PCR test results matched to a positive results of an LFT taken at a test site centre shot up in the week starting 2 September to 20% (959 of …

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