A MAJOR Covid testing change has come into force across the UK.
From January 11, anyone in England with a positive lateral flow test, undertaken at home, does not need to follow it up with a PCR test.
PCR tests are not needed for people asymptomatic people with positive Covid on lateral flowsCredit: Avalon.red
But those who have symptoms of the virus should always get a PCR as well, the new rules state.
The same rules were applied immediately in Northern Ireland yesterday, and in Scotland and Wales as of January 6.
When should you get a PCR?
You should always get a PCR test if you have symptoms of the coronavirus, regardless of your lateral flow test result.
The NHS lists the three classic signs of Covid as a new, persistent cough, a high temperature and loss of smell or taste.
However, everybody knows someone who has had Covid but didn’t have these typical features.
Scientists that track the outbreak also say fatigue, headache, runny nose, sore throat and sneezing are common with Covid.
You should also get a PCR test if you have symptoms of Covid and a positive result on a lateral flow, in order to double-check.
Dr Alexander Edwards, Associate Professor in Biomedical Technology, University of Reading, said: “The motivation for the UK system still requiring PCR confirmation more recently is likely to do with monitoring virus variants, rather than confirming the original lateral flow result.”
If you get a positive lateral flow test, but don’t have symptoms, you can assume you have the virus and should self-isolate immediately.
Your self-isolation is 10 days, starting the day after your positive result. But you can come out on day seven, if you have negative lateral flow test results on day six and seven, 24 hours apart.
There are a number of other exceptions to the rule-change, outlined by the Government:
- people who are eligible for the £500 Test and Trace Support Payment (TTSP) will still be asked to take a confirmatory PCR so they can access financial support
- people participating in research or surveillance programmes may still be asked to take a follow-up PCR test
- around one million people in England who are at particular risk of becoming seriously ill from Covid are involved in new research of treatments
- in Wales, those who are in a “clinically vulnerable” group will still need to take a PCR test.
Why have the rules changed?
Relieve pressure on testing system
The rule-change is only a temporary measure while Covid rates remain high across the UK.
The latest Office for National Statistics figures estimate that one in 15 people in England had the virus in the week to December 23.
There are huge pressures on the testing system as a result – which will be relieved by the new rules.
Wales’s health minister believes the change will reduce the demand for PCR tests by between five and 15 per cent.
Given that lateral flow test results are almost always correct for a positive result, it is unnecessary to double check with an NHS PCR test.
PCR tests are the top standard of Covid testing and are available at drive throughs, walk-ins and can be sent to the home. The lab gives results in around 24 hours.
Lateral flow tests, on the other hand, are slightly less accurate and give results in less than 30 minutes. Also called “antigen tests”, they are done at home.
Experts say a positive result is almost never wrong. But sometimes, a negative result is incorrect.
Dr Hayley Jones, Senior Lecturer in Medical Statistics, University of Bristol, said: “At current high levels of infection in the population, it’s sensible to assume you’re infectious if you have a positive lateral flow test result, without a ‘confirmatory’ PCR.
“But it’s crucial to remember that the reverse is not true: a negative lateral flow result doesn’t guarantee that you don’t have Covid-19 or that you’re not infectious.
“So it remains important to get a PCR test if you have symptoms regardless of a negative lateral flow result.”
Dr Jones also highlighted the importance of always reporting a positive lateral flow test on the government website.
Professor John Edmunds, a member of the Government’s Sage scientific advisory panel, said: “This change makes a lot of sense.
“When the prevalence is high – and it is incredibly high at the moment – almost everyone who tests positive with a lateral flow test will be a true positive.
“There is really no need to confirm this with a PCR, a step that not only wastes time but costs a lot of money and uses up laboratory resources that could be better used elsewhere.”
Prof Sir David Spiegelhalter, Chair, Winton Centre for Risk and Evidence Communication, University of Cambridge, added: “A positive LFD followed by a negative PCR would still mean it was very likely that you were carrying the virus.”
Reduce self-isolation periods
Previously, those without symptoms who tested positive on a lateral flow were asked to order a PCR test and only begin their isolation period when they received the second result.
It meant they would have to isolate for longer than seven days – particularly if there were delays in obtaining the confirmatory result.
But now, people who receive a positive result on an LFD will be required to self-isolate immediately.
The new change could limit the time staff are off work, as self-isolation begins from the positive LFD test.