Covid-19 infections in the UK climbed to a new record high in the first week of the year, though levels dropped slightly in London, new figures show.

An estimated 4.3 million people in private households across the UK had Covid-19 in the seven days to January 6, up from 3.7 million in the previous week, according to the Office for National Statistics (ONS).

All four nations saw a jump in infections, with prevalence of Covid-19 continuing to be highest in England, where around one in 15 people were estimated to have the virus – the equivalent of 3.7 million people, up from 3.3 million a week earlier.

In the other nations, prevalence was estimated at one in 20, with Wales seeing infections jump week-on-week from around 157,900 people to 169,100, Scotland up from 238,000 to 297,400, and Northern Ireland up from 72,900 to 99,200.

HEALTH Coronavirus Infections
(PA Graphics)

Infection levels are estimated to have fallen in London, however.

Around one in 15 people in the capital were likely to have had Covid-19 last week, down from a record one in 10 in the week to December 31.

So far this is the only part of the country to show a clear drop in infections, though the trend in eastern England is “uncertain”, with levels unchanged week-on-week at one in 20 people, the ONS said.

Sir Chris Whitty, England’s chief medical officer, said the figures show “we still need to keep our guard up”, tweeting: “If you have not had your first, second or booster vaccine, please come forward; they protect you and those around you.”

The number of Covid-19 infections in the UK, which is estimated every week by the ONS, is not the same as the number of new cases of coronavirus which are reported every day by the Government.

The number of infections provides a snapshot of the prevalence of Covid-19 within the entire community population of the UK, and estimates the percentage of people who are likely to test positive for the virus at any one point – regardless of when they caught the virus, how long they have had it, and whether they have symptoms.

It is based on a sample of swab tests collected from households across the UK.

By contrast, the number of cases of Covid-19 reported each day by the Government is limited only to those people who have newly tested positive for the virus, and is therefore affected by how many people are coming forward for tests, who have reported their test results, or who are taking a test because they know they have coronavirus symptoms.

The infection survey is therefore the most reliable measure of how prevalent Covid-19 is across the country.

North-west England has replaced London as the region with the highest positivity rate, with 9.8% of people likely to have had Covid-19 in the week to January 6, up from 7.8% a week earlier, the ONS said.

In Yorkshire and the Humber, the estimate has increased from 6.1% to 8.4%, while in north-east England it is up from 5.3% to 7.7%

By contrast, infection levels for London are estimated to have fallen from 8.8% to 7.8%.

All estimates are for people in private households and do not include hospitals, care homes and other settings.