A director of public health has advised people to isolate if they have symtoms of Covid-19 even if they subsequently receive a negative PCR test result.
The advice follows after GPs say they have seen “a stream of patients” who had received positive lateral flow tests, but who then went on to receive negative PCR results.
BBC reports: The UK Health Security Agency said it was investigating the cause.
But one Independent SAGE adviser has said self-isolating after a negative test may not be practical for some.
While it is understood lateral flow device (LFD) tests can sometimes produce a false negative, false positives are much rarer.
The UK Health Security Agency said it had been made aware of “some areas across the country” anecdotally reporting positive LFD results with subsequent negative PCR tests.
It added there was currently no evidence of there being any technical issues with LFD or PCR test kits in relation to those reports.
It said no test was 100% accurate, although the chances of a false positive result remained low.
A growing number of people have been taking to social media to report the phenomenon.
Many have been from Bath, Bristol and Swindon but it is also understood to be happening elsewhere in England.
Becky Reynolds, director of public health for Bath and North East Somerset Council, said the council was aware of the situation adding: “It is confusing [for people]. I think we just need to bear with it while the investigation happens”.
Ms Reynolds said the advice they had been given was that “PCR are the gold standard” and officially a negative PCR means you do not have Covid.
But she said: “The advice is also to think about your local situation, do an individual risk assessment… so what is the likelihood that even though the PCR is negative, that you may still have Covid?
“If thinking it through there is quite a chance you have Covid, even if the PCR is coming back negative, then regard it as Covid and self-isolate.”
Dr Lucy Pocock, a GP from Cadbury Heath Healthcare in south Gloucestershire, said: “Myself and my colleagues have seen a stream of patients with what we would consider very typical Covid symptoms.
“Several of these patients have done multiple lateral flow tests, all positive, and have then rightly gone on to do a PCR test, which has come back negative.
“The worrying thing here is that these people are all clearly symptomatic and with a very unexpected negative PCR result.”