Test and trace may have had no effect so far, says expert

TEST and trace may not have prevented a single case of coronavirus, a Public Health England expert has said.

Professor Noel Mccarthy, honorary consultant epidemiologist, said failing to identify most people who are infected with the disease, and slowness reaching close contacts, means the flagship system is having almost no effect.

He told the Lords Science and Technology committee that it was extremely challenging to launch such a system while levels of infection in England are still so high. And he said there was no guarantee the service would ever operate as required.

His comments come days after the latest figures for NHS Test and Trace, which launched on May 28, found the system was becoming less good at reaching close contacts of infected people.

Prof Mccarthy, from Warwick University, said that “the large majority of cases aren’t being diagnosed to enter the system and, when they do enter it, we’re only finding a small proportion of the contacts – we think, we’re not sure – and we’re finding them with a significant delay”.

He added: “So I think we’re probably preventing very few onward infections, if any, at the moment.”

He said persuading people to selfisolate requires “intense, bespoke follow-up” from highly trained staff.

Data for the third week of the new system to get England out of lockdown, released on Thursday, revealed that 81.7 per cent of close contacts were reached and advised to self-isolate between June 11 and 17, compared with 90.9 per cent the week before.

Meanwhile, only 70 per cent of people who tested positive and were uploaded onto the system were contacted by volunteers in the first place.

Prof Mccarthy told the Lords committee: “I don’t think we can say, at the moment, that there is a satisfactory safety net through testing and tracing to make a significant impact on control of the epidemic.”