Coronavirus: Only 4 in 10 Covid-19 patients contacted at start of government's 'test and trace' scheme, leaked figures show

Boris Johnson promised a 'world-beating' system would sit at the heart of the government's moves to ease lockdown

Only four in 10 coronavirus patients identified in the government’s new test-and-trace programme - and little more than one-third of the contacts they named - were contacted within the first four days of the scheme's operation, leaked figures obtained by Channel 4 News suggest.

The test-and-trace system is a key element of the government’s plan to take Britain out of lockdown without sparking a new spike in infections, and Boris Johnson has promised that it will be “world-beating”.

Despite describing the first few days of the scheme as “successful", health secretary Matt Hancock has so far declined to provide figures on the number of people contacted. Testing tsar John Newton today said the programme was "going well" and that "thousands" had been spoken to and agreed to self-isolate to prevent the possible spread of the disease.

Uncertainty about the numbers have come amid reports that some of the 25,000 tracers recruited have complained of being inadequately trained or having little to do.

Now, unverified figures obtained by Channel 4 News suggest that some 4,456 confirmed Covid-19 cases were reported to the test-and-trace teams across England between the start of operations on Thursday and Sunday.

Of these, just 1,831 had completed the required forms to provide information about their contacts either online or through a phone call by the end of the weekend.

This amounts to 41 per cent of the total.

In the forms, patients identified a total of 4,634 people who they believed they had been in contact with over the previous few days - an average of around two and a half each.

The number of contacts who were tracked down was 1,749, just 38 per cent of the total.

If all 4,456 of the confirmed Covid-19 patients had similar numbers of contacts, it suggests that as many as 11,200 people could have been close enough to them to become infected over recent days, of whom more than 9,000 were yet to be traced by Sunday.

Under the test-and-trace scheme, contacts of individuals known to have coronavirus are told to self-isolate in their homes for 14 days to prevent any further spread of the disease.

Prof Newton today confirmed that it will not be possible for asymptomatic contacts to dodge their fortnight's confinement by taking a Covid-19 test.

The nature of the virus means it may not be detectable by the test in the days before symptoms become evident, raising a risk of false negative tests, he said.

Prof Newton told the daily Downing Street coronavirus briefing: "We don't recommend testing for people who don't have symptoms because if you don't have symptoms it is unlikely to be positive and even if somebody is incubating the virus the test may well be negative.

"So if you're a contact and during the 14 days of self-isolation you have a test and it's negative, you still have to complete the 14 days' isolation. So there's little utility offering tests to people who are contacts unless they have symptoms, in which case it is worthwhile."

Prof Newton encouraged anyone concerned they may have coronavirus symptoms to get themselves tested: "As the secretary of state has said, we are really keen for anybody who has symptoms that might be coronavirus to come forward and have a test, so we can give a definitive answer and if they are positive they can be entered into the test-and-trace system.

"There are thousands of people who've already tested positive who been successfully fed into the test-and-trace programme and they have identified contacts. There are thousands of contacts who have been successfully identified and agreed to self-isolate. So that programme is going well.