LONDON (Reuters) – Rapid lateral flow tests are likely to identify the most infectious COVID-19 cases with the highest viral loads despite concerns about the overall sensitivity of the tests, researchers at Oxford University said on Thursday. British government observes massive evidence to facilitate current blockade.
Along with the deployment of COVID-19 vaccines, the government has cited widespread testing, including lateral flow testing, as a key part of its plans to reopen the economy. However, concerns about the accuracy of the tests have led some to question the plan.
Some scientists have sounded the alarm over plans by Prime Minister Boris Johnson, called “Operation Moonshot,” saying massive coronavirus testing is likely to be ineffective and costly.
Lateral flow tests are less sensitive than PCR tests, which are considered the gold standard, but can give results in just half an hour. Lateral flow tests work best among people with higher viral loads: more viruses are detected in the nose and throat.
Looking at the data from more than a quarter of a million people who have taken part in England’s testing and tracing scheme, the scientists found that the higher the viral load, the more infectious the person is.
Applying previous estimates of the sensitivity of four lateral flow devices to these findings, the researchers found that the tests would detect between 83.7% and 90.5% of the cases leading to subsequent transmission.
“We know that lateral flow tests aren’t 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 a new spread,” said Tim Peto, professor of Oxford University Medicine.
The researchers said they could not determine most of those who had been asymptomatically infected, however, “which may contribute substantially to subsequent transmission.”
(Report by Alistair Smout; Sonya Hepinstall Edition)