Cornwall and the Isles of Scilly has seen its Covid contact tracing success rate fall for the third week running, new figures reveal.

The government's chief scientific advisor Sir Patrick Vallance said there is "room for improvement" in the NHS Test and Trace system as its performance reached yet another record low nationally.

Data from the Department for Health and Social care shows 914 people who tested positive for Covid-19 in Cornwall and the Isles of Scilly were transferred to the Test and Trace service between May 28 and October 14.

Contact tracers ask these patients to give details for anyone they were in close contact with in the 48 hours before their symptoms started.

This led to 2,079 close contacts being identified over the period – also referred to as "non-complex" cases, meaning they could be dealt with through a call centre or online.

But just 66.1 per cent were reached – down from 70.4 per cent at the start of the scheme to September 23, 68.8 per cent by September 30 and 67.4 per cent by October 7.

Across England, 57.6 per cent of non-complex close contacts were reached and told to self-isolate by NHS Test and Trace in the latest week to October 14.

Including complex cases – those linked to settings such as hospitals, schools or prisons – the contact tracing rate was 59.6 per cent - the lowest percentage since test and trace began.

Read next: Coronavirus in Cornwall round up: Saturday, October 24

At a recent Downing Street press conference, Sir Patrick said it is “very clear” that there is room for improvement.

He told the press briefing: “It’s undoubtedly the case that test, trace and isolation becomes much more difficult to have an impact once numbers are high, it’s much more effective when numbers are low.”

In Cornwall and the Isles of Scilly, 178 new positive cases were transferred to test and trace in the latest week, NHS figures show.

Across England, around 97,000 cases were transferred – a figure that has increased sharply since the end of August.

Ian Hudspeth, chairman of the Local Government Association, said it is concerning that the test and trace system is "going backwards".

He added: “If we are to prevent this second wave from escalating further, we need the system to meet the recommended 80 per cent benchmark if it is to have any chance of success."

Data also shows that in the latest weekly period just 15.1 per cent of people who were tested for Covid-19 nationally at a regional site, local site or mobile testing unit – a so-called in-person test – received their result within 24 hours.

This was down from 32.8 per cent in the previous week and is the lowest rate on record.

Prime Minister Boris Johnson said at the Number 10 press briefing that he shares people's "frustrations" over the turnaround times, admitting that the system needs to improve.

Saffron Cordery, deputy chief executive of NHS Providers, which represents trusts across England, said: "These figures provide yet more evidence that the test and trace system is falling short.

"The figures on turnaround times are particularly disturbing."