Diane Schofield does 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 broke out in the UK over the use of rapid coronavirus tests – formally known as “lateral flow tests”.
A heated debate is taking place over how accurate they are in detecting Covid-19 cases and whether they should be implemented as a faster and cheaper way to conduct mass tests.
The tests can be self-administered and detect the current Covid-19 infection, with results usually within 30 minutes. They involve collecting a cotton swab from both nostrils, but not the throat, and can be processed without laboratory equipment.
The British government, which wants to see lateral flow tests implemented in more places, such as schools, says the tests are accurate and reliable and allow regular testing of people who may have the virus, but are asymptomatic.
But the tests have divided the scientific community, with critics saying the tests are less accurate than the PCR tests, which are still widely seen as the “gold standard” in terms of sensitivity and accuracy (although the results tend to take more than 24 hours). hours) and can lead to several false negative results.
The government wants to expand the testing regimes (in a strategy called “Operation Moonshot”) as this could allow for a faster exit from a third national blockade that is further damaging the British economy after a year of disruptions.
More Infectious Covid Cases
A preprint of a government-funded study by the University of Oxford was published on Thursday that concluded that “lateral flow devices detect the majority of Covid-19 infectious cases and may allow for safer relaxation of the current block.”
The study also confirmed that the more viruses detected in the nose and throat (known as viral load), the more infectious the individual is: “This is the first time this has been confirmed in a large-scale study and explains part of why some people pass Covid-19 and others don’t, “noted the study.
As such, people with higher viral loads are more likely to transmit the infection to others, making these infected individuals the most important to detect, so that they can be isolated in order to reduce progressive transmission.
The wider use of lateral flow tests may help to detect more of these highly infectious individuals who transmit the virus more easily, the study said.
“The modeling suggests that lateral flow devices would identify the individuals responsible for 84% of transmissions using the least sensitive of the four kits (lateral flow) tested, and 91% using the most sensitive,” said the study, although it acknowledged that such tests are less more accurate than PCR tests.
“Covid-19 tests that are less sensitive than standard PCR but easier to make widely available, such as lateral flow tests, can be a good solution to ensure that those who are highly infectious are able to know they need to isolate more quickly and could allow relaxation of blocking restrictions. “
“They would also allow more people to be tested with immediate results, including those who have no symptoms and people at greater risk of positive testing, for example, because of their work or because they have made contact.”
Tim Peto, professor of medicine at the University of Oxford and senior author of the study, said that “we know that lateral flow tests are not perfect, but that does not stop them from changing the game by helping to detect a large number of infectious cases with fast enough to prevent further spread. “
The UK government has planned to launch lateral flow tests in schools to conduct daily tests for coronavirus among students aged 11 to 18, in an attempt to reduce the number of children and young adults who need to stay at home and isolate themselves if they come in. contact with a positive case.
However, the plan was shelved because most schools took classes online with a third block being implemented due to the rapid increase in infections.