Government figures show 60.3% of close contacts of people who tested positive in England were reached through the Test and Trace system in the week ending November 18.
This is down slightly from 60.7% in the previous week, and is also just above the all-time low of 60.1% for the week to October 14.
Meanwhile, for cases managed by local health protection teams, 99% of contacts were reached and asked to self-isolate in the week to November 18.
For cases managed either online or by call centres, 58.8% of close contacts were reached and asked to self-isolate.
A total of 152,660 people tested positive for Covid-19 in England at least once in the week to November 18.
This is the first time since mid-August that the number has fallen week-on-week.
It is down 9% on the previous week’s total of 168,250.
A total of 50.6% of people who were tested for Covid-19 in England in the week ending November 18 at a regional site, local site or mobile testing unit – a so-called “in-person” test – received their result within 24 hours.
This is up from 38.0% in the previous week.
Prime Minister Boris Johnson had pledged that, by the end of June, the results of all in-person tests would be back within 24 hours.
He told the House of Commons on June 3 that he would get “all tests turned around within 24 hours by the end of June, except for difficulties with postal tests or insuperable problems like that”.
Of the 156,574 people transferred to the Test and Trace system in the week to November 18, 84.9% were reached and asked to provide details of recent close contacts.
This is down slightly from 85.9% in the previous week, which was the highest weekly percentage since Test and Trace began.
Some 13.6% of people transferred to Test and Trace in the week to November 18 were not reached, while a further 1.5% did not provide any communication details.