LFT Rapid Test Kit
#16,250
Two days ago, in UK: Concerns Over Conflicting COVID LFT & PCR Tests, we looked at massive reports on social media of people testing positive for COVID at home using LFT kits, but subsequently testing negative by followup lab PCR tests.
Most of these reports were centered in Southwest England, and this led to media speculation that a `new variant' might be circulating in the region - one that could evade the PCR test but was still picked up by the less accurate Lateral Flow Test.
While a new variant was not completely out of the question, Delta has an almost invincible grip right now in the UK, making faulty testing - either from the LFT home kits, or from a local lab - a far more likely culprit.
Today, the UKHSA (UK Health Security Agency) has announced the suspension of COVID testing at a private lab in the West Midlands which has apparently generated thousands of faulty COVID test results over the past month.
We aren't told what generated up to (an estimated) 43,000 inaccurate (false-negative) PCR results, only that there was `. . . no evidence of any faults with LFD or PCR test kits themselves.' While this sounds like `human error', I imagine we'll learn more in the days ahead.
First the press release from the UKHSA, then I'll have a postscript.
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 an LFD, NHS TT has investigated and testing has been suspended at a private laboratory.
Published 15 October 2021
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 (LFD).
While investigations are underway into the precise cause, NHS TT 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, UK Health Security Agency (UKHSA), said:
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, 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 of Health and Social Care (DHSC) and UKHSA. We do not wish this matter or anything else to tarnish the amazing work done by the UK in this pandemic.
UK Health Security Agency press office
Wellington House
133-155 Waterloo Road
London
SE1 8UG
This is likely an isolated incident, but I expect this will inspire greater scrutiny of negative PCR results following a positive LFT in the UK going forward. As we've discussed previously, laboratory tests are never 100% accurate, with false-negatives usually more common than false-positives.
Over the past month we've seen numerous reports of people - who have tested negative for COVID - experiencing nasty respiratory infections (see UK: `Worst Cold Ever' Trending On Social Media), and last night the UK's Independent carried the headline GPS URGE PEOPLE TO STAY HOME AS COMPLAINTS OF ‘WORST COLD EVER’ SURGE.
Regardless of whether these are due to `missed COVID' diagnoses - or simply a resurgence of less serious seasonal URIs - the advice is good. Now is not the time to be spreading respiratory infections, when local healthcare delivery systems are already overwhelmed.
Staying home if you are sick, wearing masks in public places, and getting the appropriate vaccines (COVID and Flu), can do a lot to reduce this winter's impact, and save lives.
Note: The UK's trend in COVID Cases over the past 3 months has been a slow rise, with yesterday's total > 45,000 for the first time in nearly 3 months. Since not everyone who gets COVID gets tested, and some percentage of those tests will be inaccurate, this should be be regarded as an undercount.
