Diane Schofield undergoes a lateral flow test when she arrives at the Aspen Hill Village nursing home in Hunslet, Leeds.
Danny Lawson – PA Images | PA images | Getty Images
LONDON – A battle has broken out in the UK over the use of rapid coronavirus testing – formally known as “lateral flow testing”.
There is a heated debate about how accurately they can detect Covid-19 cases and whether they should be rolled out as a cheaper and faster way to perform mass testing.
The tests can be self-administered and detect current Covid-19 infection, with results usually within 30 minutes. They involve taking a cotton swab from both nostrils, but not from the throat, and can be processed without laboratory equipment.
The UK government, which wants lateral flow tests to be rolled out to more institutions, such as schools, says the tests are accurate, reliable and allow regular testing of people who have the virus but are asymptomatic.
But the tests have divided the scientific community, with critics saying the tests are less accurate than PCR tests, which are still widely seen as the “ gold standard ” in terms of sensitivity and accuracy (although results usually take longer than 24 hours), and can lead to multiple false negative results.
The government is keen to expand testing regimes (in a strategy dubbed “Operation Moonshot”) as this would allow for a faster exit from a third national lockdown that further hurts the UK economy after a year of disruptions.
Most Covid infectious cases
A preprint of a government-funded study from the University of Oxford was published Thursday, which concluded that “lateral flow devices detect the most infectious cases of Covid-19 and allow a safer relaxation of the current lockdown.”
The study also confirmed that the more viruses detected in the nose and throat (known as the viral load), the more contagious the individual is: “This is the first time this has been confirmed in a large-scale study and partly explains why some people pass on Covid-19 and others don’t, ”noted the study.
As such, people with a higher viral load are more likely to pass the infection on to others, making these infected individuals the most important to detect so that they can be isolated to reduce further transmission.
The wider use of lateral flow testing could help pick up more of these highly contagious individuals who transmit the virus more easily, the study said.
“Modeling suggests that lateral flow devices would identify individuals responsible for 84% of transmissions using the least sensitive of the four (lateral flow) kits tested, and 91% with the most sensitive,” said the study, although it was recognized that such tests are fewer. accurate than PCR tests.
Covid-19 tests that are less sensitive than standard PCR but can be made more widely available, such as lateral flow tests, could be a good solution to make sure those who are highly contagious know they are need to isolate faster and can make it possible to relax the lockdown restrictions. “
“They would also allow more people to be tested with immediate results, including those who have no symptoms and those at increased risk of testing positive, for example because of their job or because they themselves have been a contact person.”
Tim Peto, Professor of Medicine at the University of Oxford and senior author of the study, said that “we know that lateral flow tests aren’t perfect, but that doesn’t stop them from being a game changer for helping detecting large numbers of infectious cases fast enough to prevent further spread. “
The UK government planned to conduct lateral flow testing in schools to conduct daily coronavirus testing among students aged 11 to 18, in an effort to reduce the number of children and young adults who have to stay home and isolate themselves when they come in contact with a positive case.
However, the plan was shelved because the majority of schools took online classes and a third blockade was implemented due to a rapid increase in infections.