Diane Schofield performs a side flow test when she arrives at the Aspen Hill Village nursing home in Hunslet, Leeds.
Danny Lawson – PA Pictures Images PA | Getty Images
LONDON – A battle has broken out in the UK over the use of rapid coronavirus tests, formally known as “lateral flow tests”.
There is a heated debate about the accuracy of detecting Covid-19 cases and whether they should be deployed as a faster and faster way to conduct mass testing.
Tests can be self-administered and detect current Covid-19 infection, with results typically within 30 minutes. It involves taking a swab from both nostrils, but not from the throat, and it can be processed without laboratory equipment.
The British government, which wants lateral flow testing to be carried out in more settings, such as schools, says the tests are accurate and reliable and allow for regular testing of people who may have the virus but are asymptomatic.
But the tests have divided the scientific community, and critics say the tests are less accurate than PCR tests, which are still widely regarded as the “gold standard” in terms of sensitivity and accuracy (although the results they usually take more than 24 hours)), and could lead to multiple false negative results.
The government is interested in expanding test regimes (in a strategy called “Operation Moonshot”), as it could allow a quicker exit from a third national closure that would further hurt the British economy after a year of interruptions.
More infectious Covid cases
A preview of a study funded by the Oxford University government was published on Thursday, concluding that “lateral flow devices detect most cases of Covid-19 infection and could allow a safer relaxation of the current blockade.”
The study also confirmed that the more virus is detected in the nose and throat (known as viral load), the more infectious the individual is: “This is the first time it has been confirmed in a large-scale study and explains part of why some people outperform Covid-19 and others don’t, ”the study noted.
As such, people with higher viral loads are more likely to transmit the infection to other people, making these infected people the most important to detect, so they can be isolated to reduce subsequent transmission.
Wider use of lateral flow tests could help capture more of these highly infectious individuals who transmit the virus more easily, according to the study.
“Modeling suggests that lateral flow devices would identify individuals responsible for 84% of transmissions using the four least sensitive (lateral flow) kits tested and 91% of the most sensitive,” the study said, though who acknowledged that these tests are less accurate than PCR tests.
“Covid-19 tests that are less sensitive than standard PCR, however, easier to make available, such as lateral flow tests, could be a good solution to ensure that those who are highly infectious can know they need to isolate- faster and could allow for a reduction in blocking restrictions. “
“They would also allow more people to be tested to give immediate results, including those who have no symptoms and people at higher risk of giving positive, for example, because of their work or having been in contact themselves.”
Tim Peto, a professor of medicine at Oxford University and lead author of the study, said: “We know that lateral flow tests are not perfect, but that doesn’t stop them from being a game changer to help detect a large number of infectious cases quickly enough to prevent further spread. “
The UK government planned to launch side flow tests in schools to conduct daily coronavirus tests among pupils aged 11 to 18, with the aim of reducing the number of children and young adults who should be stay home and isolate themselves if they came. in contact with a positive case.
However, the plan was dropped as most schools took online classes and a third blockade was implemented due to a rapid increase in infections.