British no-swab coronavirus test gives effective results in 20 minutes

OptiGene test proves highly sensitive to the infection, even among people who do not show symptoms

People wear masks on a train platform at Waterloo Station in London. Reuters

A speedy coronavirus test that can be taken without the need for a nose or throat swab has a high sensitivity to the virus, according to the UK government.

The test takes 20 minutes and has been found to be highly effective in identifying the infection, including among people who do not show symptoms, it said on Tuesday.

The RT-Lamp tests, made by privately held British company OptiGene, were studied in a pilot programme in Southampton, southern England, where they were used to test some health service staff, as well as 55,000 people connected to the university in the city.

Initial results from the pilot tests showed they were effective in identifying Covid-19 cases and breaking chains of transmission.

"We've shown through carefully conducted studies that the OptiGene Lamp test is fast, reliable and easy to use, and dependent on testing format can work directly with saliva samples, as well as with swabs," said Sue Hill, chief scientific officer for England in the National Health Service's test and trace programme.

Lamp is short for loop-mediated isothermal amplification, the technology used to process the tests.

The tests can produce results quicker than the commonly used PCR tests.

In the pilot programme, the tests were used in four different configurations, involving swabs as well as saliva.

The Health Ministry said the tests were found to have a sensitivity of 79 per cent and specificity of 100 per cent, meaning they are effective in identifying people who were most likely to transmit the disease.

"In samples with a higher viral load, the sensitivity of the test increased to 94 per cent for saliva and 100 per cent for swabs," the ministry said.

Lateral flow tests, which are similar to pregnancy tests, that give results in minutes and can be carried out without supervision are part of a pilot mass testing initiative in Liverpool.

But some experts said rapid tests were not as accurate as PCR tests processed in a lab and could result in people who are infectious being told they are not.

The government said that, unlike PCR tests, OptiGene's testing does not require sequential changes of temperature and so can produce results more quickly.

“With up to a third of individuals with Covid-19 not displaying symptoms, we are rolling out asymptomatic testing to protect those at highest risk," Lord Bethell, undersecretary of state at the Department of Health and Social Care, said.

“By broadening testing to identify those showing no symptoms and who can infect people unknowingly, we can find positive cases more quickly and break chains of transmission."

Sensitivity indicates the proportion of people with a disease that test positive, while specificity refers to the proportion of people without the disease that have a negative test.

The measures are also used to determine the levels of false positives and false negatives.

Keith Godfrey, a professor of epidemiology at the University of Southampton, who led part of the pilot initiative, said it had been a success.

"The saliva Lamp project in Southampton has proved to be very easy for students to use and is extremely popular with parents and staff," he said.