Contact tracers are still struggling to reach people who have been in close contact with Covid-19 patients.

The contact tracing success rate in Hertfordshire has fallen for the sixth week running. Meanwhile, there have been a record number of new positive cases.

Data from the Department for Health and Social care shows 10,405 people who tested positive for Covid-19 in Hertfordshire were transferred to the Test and Trace service between May 28 and November 11.

That means 1,911 new cases were transferred in the latest seven-day period – the largest increase since the regime began.

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

This led to 25,035 close contacts being identified over the period – those not managed by local health protection teams, which are dealt with through a call centre or online.

Read more: Herts could leave lockdown with tougher restrictions than before

But just 61.6 per cent were reached – a figure that has fallen steadily over a six-week period.

Across England, 58.9 per cent of contacts not managed by local health protection teams were reached and told to self-isolate by NHS Test and Trace in the latest week to November 11.

Local health protection teams deal with cases linked to settings such as hospitals, schools and prisons.

The contact tracing rate including these cases was 60.5 per cent– in line with the week before.

Around 157,000 new cases were transferred nationally in the week to November 11, the highest weekly number since NHS Test and Trace was launched.