The privatised Test and Trace system is suddenly reaching 92% of coronavirus contacts after a major change to how the figures are counted.
The service, run by outsourcing giants Serco and Sitel, claimed to reach 92.7% of close contacts of people with coronavirus in the week to December 9.
That is up from 85.9% the week before and around 60% for much of the Autumn.
However, it is partly due to a major change to how figures are calculated.
Previously, every member of a household - including children - counted as a separate contact to be traced individually.
Under a series of rule changes, from November 18 under-18s are no longer individually traced.
And from November 27, other adults in the same household as someone who’s already been traced are not contact-traced either.
It comes after complaints that call handlers were wasting time making multiple calls to people in the same household while ignoring others.
But it could raise questions about how the figures are released or whether people are all going to be contacted correctly in future.
“These changes have been implemented acting on feedback the service has received from families and should see a reduction in the number of calls received by households with children,” Test and Trace said in a statement.
“This change will also optimise the productivity of the tracing service by minimising the number of calls made.”
Some 109,167 people tested positive for coronavirus at least once in England in the week to December 9.
The number of people testing positive this week has decreased by 35% since this peak, but there has been an increase compared to the previous week.
Some 6.2% of people who were tested came back positive, an increase from the 5.9% reported the previous week.
