The programme of mass coronavirus testing in schools has been called into question by experts.
Academics warned that the testing strategy proposed by government could actually increase cases of Covid-19 in schools.
Plans were put in place to start mass testing in schools from January but then schools were forced to shut their doors to most pupils during the latest national lockdown.
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The testing strategy will involve staff at secondary schools and colleges in England being offered weekly tests.
And a "serial testing" scheme will mean pupils and staff will be tested if they come into contact with a positive case.
This approach, also known as "daily contact testing", will allow those who are in close contact with someone who has tested positive to return to school or college if they agree to be tested for seven days following their last contact with a positive case and that test is negative.
Fears over the reliability of Covid tests
During last term, if someone was identified as a close contact of a Covid case they would be sent home to self-isolate.
Writing in The BMJ, experts warned that using the new Covid testing strategy to manage classroom outbreaks, without isolating close contacts, risked increasing the spread of the virus.
The article, written by a number of experts including Jon Deeks, professor of biostatistics at the University of Birmingham and research lead for the Cochrane Covid-19 test evaluation review, states: “Scientists have particular concerns that negative Innova (lateral flow tests) results are too inaccurate to rule out Covid.”
They said that the serial testing of close contacts “may increase rather than decrease Covid cases in schools”.
This is because “the possibility that some close contacts who are infected will test negative and will spread the virus is not negligible”.
They said this strategy is “contrary” to scientific guidance.
This type of mass testing could detect some pre-symptomatic cases but will “miss many” and “falsely reassure those testing negative, if they are not properly informed of the test’s limitations”, the authors said.
“Home isolation impacts hard on children, families and teachers,” the article concludes. “But if Innova testing in schools risks spreading the disease more widely, it may lead to even more disruption to education and putting many more people at risk.”