The government insists on the rule that the aggressive Covid rapid test conducted in England’s secondary schools cannot be overturned by the gold standard test handled by the laboratory.
Testing experts raised a concern that many people may be mistakenly told that they have been infected.
They called for all positive results obtained in rapid tests conducted in schools to be confirmed by standard PCR tests.
This means that a student who passes a rapid field test (called a lateral flow test) at home and tests positive will have to be isolated on the basis of the test, but will be told to undergo a PCR test in the laboratory.
But for those jobs done in school-three tests will be provided to students in the next two weeks-the horizontal flow test can be considered correct. The PCR test cannot overturn the lateral flow test.
After the school started the rapid test last week, his son’s test result was positive, so Mr. Patton arranged for the 17-year-old child to undergo a PCR test, which turned negative again.
The Royal Statistical Association is one of the institutions that wants to see all positive tests confirmed by the school through PCR tests to avoid such situations.
Professor Sheila Bird, a member of the Association’s Covid-19 working group, said that “false positives are extremely likely under the current circumstances” because large-scale testing and low infection rates mean that the number of false positives may exceed the real positive factors. .
She told BBC Radio 4’s “Today’s Program” that the chance of false positives was “very low”. In the false positives, elementary school students were mistakenly diagnosed as having the virus.
She said that students who test positive through the horizontal mobility test conducted by the school will need to be isolated from their families and close contacts and “should not undergo PCR”.
She said: “What is really important is to ensure that we can keep the school open and minimize the risk of Covid in the classroom.”
As the ministers have suggested, the chance of false alarms may be small. However, given that the test is being provided to millions of school children, it may still cause thousands of people to self-isolate for no reason.
If only half of the students take the school’s three exams, and the false positive rate is 0.1%, it will result in about 6,000 students being quarantined in the next week or so without infection.
Their other family members will also have to be isolated, which means that if they have siblings, they will also be absent from school. More importantly, if the positive comes from the second or third test, the close contact of the person at school will also be affected.
This means that thousands of children may be mistakenly denied the opportunity to go to school after they have spent the past two months at home.
But what confuses experts is that it is so unnecessary. This problem can be solved by confirming the test by the PCR test processed in the laboratory. Through perseverance, the ministers may eventually undermine the entire initiative.
It is not clear what the correct false positive rate is in a school environment. The Public Health England study shows that for every 1,000 tests completed, the number may be as high as 3, but other studies have shown that this number is closer to this number.
Tests conducted on the children of key staff and teachers in schools in recent weeks have shown that the number of tests that returned positive results is consistent with lower estimates, indicating that a large number of tests may be false positives.
Dr. Kit Yates, a mathematical biologist at the University of Bath, warned that the government’s position could undermine confidence in the testing policy.
“If a more accurate PCR test cannot be used to confirm the less accurate lateral flow positivity, it will prevent people from testing the child. It’s that simple.”
Elementary school students are not required to take a quick test, but families can require the test to be used at home.
The palace said that “memories may be different,” but questions in the TV interview will be handled privately.
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Post time: Mar-10-2021