The government must implement mass community tests across England to detect people who have Covid-19 but have no symptoms.
The program, announced by health secretary Matt Hancock on Sunday morning, will allow all 317 local English authorities to offer rapid tests. They will use “lateral flow” devices, which provide results in half an hour, but are less accurate than laboratory PCR tests considered the gold standard for diagnosing infection.
The councils will be encouraged to target the test to people who cannot work at home during the block, so that they can isolate themselves if they are carrying the virus.
The government is also asking companies – mainly in the food, retail, energy and manufacturing sectors – to participate in the asymptomatic test. Companies that already run pilot programs include Apetito, John Lewis, Octopus Energy, Tate & Lyle and Tata Steel.
“With about a third of people with coronavirus showing no symptoms, targeted asymptomatic testing and subsequent isolation are highly effective in breaking down transmission chains,” said Hancock.
“Lateral flow tests have already been extremely successful in finding positive cases quickly – and all positive cases found are helping to stop the spread – so I encourage employers and workers to accept this offer,” he added.
But scientific experts have given the launch of tests a mixed reception, with reactions ranging from “this is very welcome and long overdue” to “additional implementation of lateral flow tests is very worrying”.
Some expressed concern that lateral flow tests omit many cases to be a reliable guide – mainly because samples from infected people without symptoms are likely to contain less virus than those from people with obvious illnesses.
Tom Wingfield, a senior clinical speaker at the Liverpool School of Tropical Medicine, noted that a pilot project using Innova’s lateral flow tests in Liverpool during November “lost 60 percent of Covid-19 cases,” according to a provisional assessment.
“There was no clear evidence that the strategy independently led to a reduction in cases and hospitalizations locally,” said Dr. Wingfield.
Jon Deeks, professor of biostatistics at the University of Birmingham, said that mass testing using lateral flow technology “carries a real risk of increasing rather than decreasing the spread of Covid. The government seems to focus only on the benefits of the tests – that of detecting asymptomatic cases not previously detected – and not on the damage caused by wrongly informing people that they do not have Covid-19 infection, when in fact they do. “
Adam Finn, a professor of pediatrics at the University of Bristol, said the authorities would have to make it clear to people being tested that lateral flow produces “red light” results.
“If they are positive, it means that you are potentially infectious to others and should isolate yourself,” he said. “They are not ‘green light’ tests. You cannot be sure that if the test is negative you are not infectious and should continue to take the usual precautions. ”
With that caveat, Prof Finn said, “this provides an important new tool to help reduce the rapid increase in cases that is paralyzing our country.”
Professor Lawrence Young, a virologist at Warwick Medical School, also cautiously welcomed the mass testing initiative.
“Asymptomatic testing of individuals who cannot stay at home during the current block will help to restrict the spread of the infection, as long as we ensure that people with positive results are adequately isolated and that their contacts are tracked and isolated,” he said. he. “Repeating the test is essential, given the nature and timing of the virus infection and concerns about the accuracy of lateral flow tests.”