Data compiled by the Covid-19 Actuaries Response Group show the proportion of people likely to have caught Covid in hospital grew by 29 per cent this week.
The research, published in the Independent, showed that in the 28 days leading up to 5 June more than 2,267 out of 13,416 patients who tested positive in hospitals were likely to have caught the virus there.
Researchers also warned the data may underestimate the figures given that routine testing has been dropped and hospitals stopped testing patients on admission in May.
One doctor told the newspaper: “Hospitals can’t help but spread infection because staff aren’t enabled to limit airborne transmission, and it only takes one on the ward, without mechanical ventilation, to lead to dozens of onward cases.
“I know of a recent outbreak which took out 14 staff; we weren’t allowed to test the whole ward, so no idea how many patients got infected.”
Britain’s overall number of cases has risen for the first time in two months, with 953,900 testing positive in the last week compared to 953,000 in the week prior.
Covid-19 infections in the UK are no longer falling, with some parts of the country showing early signs of a possible increase, figures show.
The rise is likely to have been caused by a jump in infections compatible with the original Omicron variant BA.1, along with the newer variants BA.4 and BA.5.
It comes as separate figures suggest the recent drop in the number of people in hospital with Covid-19 may also have come to a halt.
A total of 989,800 people in private households in the UK are estimated to have had the virus in the week ending June 2, up from 953,900 the previous week, according to the Office for National Statistics (ONS).
It is the first time total infections have risen week-on-week since the end of March, when the number hit a record 4.9 million at the peak of the Omicron BA.2 wave.