Oxford University’s programme to test the student population before they left for the Christmas vacation saw 27 positive tests recorded, according to data released by the University’s COVID Response department.
4,536 students were issued lateral flow tests from 30th November ahead of the travel window. Students were advised to return home between December 3rd-9th to reduce the risk that they would seed new COVID outbreaks. These self-administered tests were to be taken three days apart, with the second being taken as close to their departure as possible.
The data shows that 0.59% of tests administered were recorded as positive. It is unclear how many of the 27 individuals who had to take confirmatory PCR tests were positive for COVID-19 since these results were combined with others from the testing service. However, lateral flow tests are highly specific once they detect a COVID-19 infection, having a false-positive rate of 0.32%
There have been concerns about the reliability of lateral flow tests. While a review by Oxford University found they could pick up 76.8% of cases, rising to over 95% for people with high viral loads, their sensitivity has been lower in “real-world” scenarios. When mass-testing of the public was trialed in Liverpool, accuracy fell to 58%. This means that in a situation where the public were administering their own tests with little training, up to half of COVID-19 cases would be missed.
Scientists have warned that mass-testing the public can lead to a false sense of security, encouraging people who test negative to engage in risky behaviour. Professor Jon Deeks from Birmingham University expressed concern that people would misunderstand the results of their lateral flow tests, telling The Guardian “a negative test indicates your risk is reduced to between a quarter and one half of the average, but it does not rule out Covid. It would be tragic if people are misled into thinking that they are safe to visit their elderly relatives or take other risks.”
There have also been concerns that mass-testing university students was a “recipe for chaos”. Taking a test was not made compulsory, leading the University and College Union to warn that students who did not take the test because they did not want to risk self-isolating at university could seed new outbreaks. Both undergraduates and graduates were eligible for tests at Oxford. With a student population of 24,000, that means fewer than 20% of students took at least one lateral flow test.
Oxford University says students are “strongly advised” to take lateral flow tests when they return in Hilary Term. These will be provided by colleges. Students are advised to return early enough to take two lateral flow tests three days apart before their subject resumes face to face teaching.
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