High hopes for saliva test

Turnaround time could be as little as one hour, say experts in battle to meet target

A SALIVA test for coronavirus could help meet Boris Johnson’s 24-hour target for identifying whether a patient has the disease.

The Government is in talks with a British firm about introducing a test that would involve people suspected of having Covid-19 spitting into a tube and posting the sample to a lab.

And one expert involved with the project said the turnaround time could end up being as short as an hour.

The Prime Minister has promised that by the end of the month the majority of test results will be produced within 24 hours.

Health officials have been holding talks with Chronomics, a firm producing a saliva test. It could be examined at many more labs than swab tests, because the tube contains a solution that “inactivates” the virus.

Under Government rules, live samples of the virus can only be examined by labs with specialised equipment that conforms to its highest “containment level”.

Philip Beales, a professor at the University College London Institute of Child Health, has been helping to coordinate the efforts of smaller firms in the field of virus testing.

He said: “The test has this … buffer which inactivates the virus, preserves the RNA and then in thousands of [labs] in the country, you can just do a straightforward RNA extraction.”

He added: “Our guys are working on a one hour turnaround time from receipt of the sample in the lab, to getting the actual result back.”

Chronomics is understood to be doing a final study with Public Health England to validate its kits, while it holds discussions about providing the tests for use in the NHS and the Government mass testing programme.

Last month, Matt Hancock, the

Health Secretary, disclosed that the Government was “working with many top names to help us deliver testing with a rapid turnaround – names like Oxford Nanopore and Chronomics”.

Prof John Newton, the Government’s testing tsar, said: “The saliva testing is a really interesting one … So we are actively looking at those and we are engaging with the companies.”

The Chronomics test, designed by Nonacus, another British firm, would involve patients spitting sputum into a tube provided in hospital or sent to their homes. The sealed tube would then be sent to a lab for testing.

In late April, a Yale study suggested that saliva tests were a “more sensitive” alternative to the nose and throat swab tests now administered across the UK.

Some doctors fear that many patients fail to take an adequate sample of viral RNA from their nose or throat, leading to false negative results.

The apparent sensitivity of the saliva tests has led to optimism that workplace testing of asymptomatic staff could become routine.

The Sunday Telegraph first reported on the tests in April, when Prof Beales criticised PHE for being too slow to provide RNA samples from Covid-19 positive patients to validate the saliva tube tests.

Yesterday, experts warned that tests taking longer than 48 hours to provide results risked rendering the track and trace system useless. Up to 20,000 coronavirus tests a day are taking longer than two days to provide results.

Scientists advising the Government on track and trace predict this could lead to a 50 per cent increase in the number of infections.

Those who have been in contact with a person with Covid-19 are only notified when a positive test result is returned.

20,000

The number of coronavirus tests in the UK returned within more than 48 hours in the UK, putting track and trace in jeopardy