Lateral flow tests 95% effective at detecting Covid

Rapid Covid tests which give results in 30 minutes are 95 per cent effective at detecting Covid-19, new research has found.

Previous studies had suggested that lateral flow tests (LFT) may be less sensitive than the more expensive PCR assessments which have to be sent to laboratories for results.

However, a study of more than 2,500 people with flu-like symptoms found the LFTs pick up the vast majority of cases if used at the onset of infection.

They picked up 95 percent of the coronavirus cases that the PCR tests did and correctly identified 89 per cent of cases as negative.

The study, carried out by Queen Mary University of London, Oxford University, the Institute for Advanced Studies in Vienna and the Medical University of Graz, was the first to compare the two testing methods on the same group of people on a large scale.

LFTs function in a similar way to pregnancy tests and look for coronavirus proteins to detect cases.

Dr Werner Leber from Queen Mary University of London said: "Previous studies have suggested lateral flow tests may be less sensitive than PCR in detecting Covid-19, particularly among asymptomatic individuals and during the early or late stage of an infection when the viral load is lowest.

"But we have found that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy.

"Countries are considering using lateral flow tests to manage future waves of the pandemic. Our findings support this move, but ensuring tests are properly administered should be integral to any strategy."

Study patients were assessed by GPs in Liezen, Austria.

Dr Jasmina Panovska-Griffiths from the Big Data Institute and The Queen's College at University of Oxford added: "In our study, both shorter duration of symptoms and higher viral load were significantly associated with positive lateral flow tests.

"This highlights the necessity of testing at early infection with lateral flow tests, and shows that in patients who are newly symptomatic, the two testing methods have similar levels of accuracy.

"Our study is the first study to demonstrate that point-of-care antigen testing using lateral flow tests combined with clinical assessment of symptomatic patients can rapidly and accurately detect Sars-CoV-2 infection in primary care."