School Rapid Test Cannot Be Overruled, Says Minister

The number of secondary school pupils able to return to the classroom will be limited by the Government’s insistence that a positive lateral flow test result in a school cannot be overruled by the standard PCR test. Schools Minister Vicky Ford has said that pupils who test positive via the lateral flow tests will need to isolate, along with their families and close contacts and “should not take a PCR”. The BBC has the story.

The Government is sticking to the rule that a positive rapid Covid test done in secondary schools in England cannot be overruled by the gold-standard tests processed by labs.

Concerns have been raised by testing experts that significant numbers could be incorrectly told they are infected.

They have called for all positives from the rapid testing done in schools to be confirmed by the standard PCR test.

This is what will happen when testing is done at home after next week.

It will mean a pupil who tests positive at home with a rapid on-the-spot test – known as a lateral flow test – will have to isolate on the basis of that test, but will be told to get a PCR test which is processed in a lab. 

If that PCR test is negative they will be released from isolation.

But for those done in schools – pupils are being offered three tests in the next two weeks – it will be assumed the lateral flow test is right. A PCR test cannot overrule the lateral flow test.

The article draws attention to specific examples of failures taking place under this system:

One of those who has been affected already is the family of Richard Patton, from Derbyshire.

His son’s school started rapid testing last week and he tested positive. Mr Patton arranged for his 17 year-old son to get a PCR test, which came back negative.

But the whole family, including his 15 year-old daughter, is still having to isolate at home.

“It makes no sense. They were looking forward to going back to school and are now stuck at home.”

BBC health correspondent Nick Triggle points out that even if the chance of false positives is very low, “it could still lead to thousands of people having to self-isolate for no reason”.

If just half of pupils take up the offer of three tests in school and the false positive rate is 0.1% that could still lead to around 6,000 pupils being asked to isolate at home over the next week or so when they are not infected.

Tiggle makes a good point. Given the low prevalence of the virus and the false positive rate of the lateral flaw test, a majority of positive results in schools will be false positives, as Sheila Bird, a member of the Royal Statistical Society, has pointed out in a new paper.

Worth reading in full.

Stop Press: The Government has now said that if a child tests positive in a lateral flow test but negative in a PCR test, they will not have to self isolate, according to ITV News’s UK Editor Paul Brand.