UK Health Security Agency has reminded citizens that PCR lateral flow tests are far more accurate than lateral flow tests, which anyone can obtain free of charge from NHS
A public health chief has warned anyone who has Covid-19 symptoms but has tested negative to still self-isolate.
Medics are reporting seeing increasing numbers of patients who had received positive lateral flow tests but went on to receive negative PCR results.
Doctors say PCR tests are far more accurate than the lateral flow ones, which can currently be obtained for free from the NHS.
The UK Health Security Agency said the phenomenon has been particularly prevalent in the southwest of England.
“It is confusing [for people]. I think we just need to bear with it while the investigation happens,” Becky Reynolds, director of public health for Bath and North East Somerset Council, 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.”
UK Health Security Agency is investigating the cause but said there is currently no evidence of there being any technical issues with Lateral flow or PCR test kits.
But Dr Lucy Pocock, a GP from Cadbury Heath Healthcare in south Gloucestershire, told BBC: “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.”
A member of the Independent Scientific Advisory Group for Emergencies [SAGE], Kit Yates, has called for the situation to be looked into “seriously and rapidly”.
Chief medical advisor for the UK Health Security Agency, Susan Hopkins, said: “We have been made aware of some areas reporting positive Lateral Flow Test test results with subsequent negative PCR tests and we are looking into the cause.”
She said it was vital to carefully read and follow the instructions for use on the test kit in order to avoid any incorrect readings.