The latest data on England’s contact tracing system will be published today amid concerns about the effectiveness of the operation.
Experts have warned that the NHS Test and Trace system must rapidly improve to cope with the pressures expected once schools fully return in September and as winter approaches.
Labour leader Sir Keir Starmer warned that time is running out to fix the system before pupils return to classes.
“The test, trace and isolate system is critical but it’s still not working properly,” he said.
“Time is running out for the Government to fix it.”
Last week’s figures showed the system – which Boris Johnson said would be “world beating” – was unable to reach a quarter of the contacts provided by infected people.
In recent days scientists have voiced concerns about how well the system will be able to cope over the winter, a time when the Prime Minister wants a “more significant return to normality”.
The authors of a modelling study said that without appropriate levels of testing and contact tracing, reopening of schools together with gradual relaxing of the lockdown measures are “likely to induce a second wave that would peak in December 2020 if schools open full-time in September”.
The study by researchers from UCL and the London School of Hygiene and Tropical Medicine (LSHTM), published in The Lancet Child And Adolescent Health, warned that in a worst-case scenario a second wave could be 2.3 times higher than the first.
But its authors said that “with increased levels of testing… and effective contact tracing and isolation, an epidemic rebound might be prevented”.
One of the authors, Chris Bonell, professor of public health sociology at LSHTM, said the key message from the modelling paper was that the “test, trace isolate system is critically important and getting better but coverage must further increase”.
He said the actual coverage provided by the current system was around 50%, because last week’s figures showed only 81% of positive cases were referred to the contact-tracing operation, 81% of those were reached and asked to provide contacts and 75% of those were reached and asked to self-isolate.
Reports have suggested that some contact tracers working for the NHS Test and Trace programme in England are making just a handful of calls a month.
The Department of Health and Social Care has defended the record of the system.
“In just eight weeks, NHS Test and Trace has tested more than 2.6 million people for coronavirus and contacted more than 218,000 people who have tested positive for the virus, or recently been in contact with someone who has tested positive – in order to break the chain of transmission,” a spokesman said.
Some councils have taken matters into their own hands and launched local contact-tracing operations to supplement the national system.
Calderdale Council, which covers Halifax and surrounding areas, is the second authority to make the move after Blackburn and Darwen said it was setting up a locally focused system to utilise community knowledge.
Meanwhile in Scotland, bars, cafes and restaurants in Aberdeen were ordered to close over a coronavirus cluster in the area.
A five-mile travel rule has been put in place and residents are being told not to enter each other’s houses.
First Minister Nicola Sturgeon said there were concerns about “a significant outbreak in Aberdeen that may include some community transmission”.