Why quick Covid tests are causing a stir in the UK


Diane Schofield takes a side flow test when she arrives at the Aspen Hill Village nursing home in Hunslet, Leeds.

Danny Lawson – PA Pictures | PA pictures | 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 going on about how exactly they detect Covid-19 cases and whether they should be introduced as a cheaper and faster way to do mass testing.

The tests can be done by yourself and detect the current Covid-19 infection, with the results usually being available within 30 minutes. They involve taking a swab from both nostrils, but not the throat, and can be used without laboratory equipment.

The UK government, which wants lateral flow testing to be introduced in more facilities like schools, says the tests are accurate, reliable, and allow regular testing of people who may have the virus but are asymptomatic.

However, the tests have divided the scientific community. Critics say the tests are less accurate than PCR tests, which are still generally considered the “gold standard” for sensitivity and accuracy (although results typically take longer than 24 hours) and could produce multiple false negative results to lead.

The government is keen to expand the testing regime (in a strategy known as “Operation Moonshot”) as this could allow a faster exit from a third national lockdown that is further damaging the UK economy after a year of disruption.

Most infectious Covid cases

A preprint of a government-funded study by Oxford University was released on Thursday that concluded that “lateral flow devices could detect most infectious Covid-19 cases and provide safer relaxation of the current lockdown”.

The study also confirmed that the more viruses found in the nose and throat (known as viral load), the more contagious the individual is: “This is the first time this has been confirmed in a large-scale study and explains part of it why some pass on Covid-19, others don’t, “the study says.

Therefore, people with higher viral loads are more likely to pass the infection on to others, making those infected people the most important to identify so that they can be isolated to reduce further transmission.

The wider use of lateral flow tests could help ingest more of these highly infectious people who are more likely to transmit the virus, the study said.

“The modeling suggests that lateral flow devices would identify people who are responsible for 84% of transmissions by using the least sensitive of four tested (lateral flow) kits and 91% the most sensitive,” says it in the study, although they realized that such tests are less accurate than PCR tests.

“Covid-19 tests that are less sensitive than standard PCR but are easier to make widely available, such as lateral flow tests, could be a good solution to ensure that highly infectious people know that they have to isolate faster and in a more isolated manner could allow the lockdown restrictions to be relaxed.

“They would also allow more people to be tested, which leads to immediate results, including those who have no symptoms and people at an increased risk of testing positive, for example because of their work or because they have had contact.”

Tim Peto, Professor of Medicine at Oxford University and lead author on the study, said, “We know that lateral flow tests are not perfect, but that doesn’t prevent them from playing an important role in detecting large numbers of blood cells . ” Cases of infection fast enough to prevent further spread. “

The UK government had planned to run lateral flow tests in schools to run daily coronavirus tests on students ages 11-18 to reduce the number of children and young adults staying at home and self-isolating must when they come into contact with a positive case.

However, the plan was put on hold as the majority of schools took classes online and a third lockdown was in place due to a rapid surge in infections.