Thousands of families of care home residents are facing fresh distress as operators enforce tighter visitor restrictions and lock down homes as Covid-19 infections rise.

Care UK, one of the largest national operators, has already closed 48 of its 124 care homes to visitors, mostly because of positive tests or because it is awaiting test results. HC One, the largest UK operator, said it had recorded increasing numbers of infections among a small number of staff. Some 133 of its homes are now closed to visitors, and it is restricting visits where wider community infection is high.

Local outbreaks combined with operators’ determination to avoid being overwhelmed by the virus for a second time are driving the moves. This spring and early summer, more than 15,000 people died of confirmed or suspected Covid-19 in English care homes.

Many operators had been planning to ease restrictions and allow more indoor visits this winter. Among them was the Orders of St John Care Trust, which looks after 3,000 residents in 84 homes in Wiltshire, Oxfordshire, Lincolnshire and Gloucestershire. It is now considering tighter visiting restrictions instead.

Providers in Norfolk and Sheffield said they were considering the same and concern for the health of residents has been compounded by insurers withdrawing cover for Covid-related risks. Care homes in areas under wider local lockdowns, such as Tameside in north- west England, have already closed their doors.

The moves come as figures show an increase in positive coronavirus tests in care homes. In the week ending 6 September, 4.2% of infections in England were in care homes – equivalent to 513 cases, Public Health England data shows. The previous week the proportion was 2%, equivalent to 159 cases. Infections rose further last week, according to a government briefing to the sector.

Greater lockdowns are likely to mean anguish for relatives. Many wanted greater access fearing their loved ones’ health has deteriorated rapidly in isolation.

Gabriella Thomas, 56, whose mother, Edda Thomas, 82, is in a dementia care home in Berkshire, said tighter restrictions would be unacceptable.

“It’s incredibly hard,” she said. “She doesn’t really recognise me when I go and she doesn’t remember her grandson any more.”

Jayne Macrae, 51, was stopped from seeing her 73-year-old mother earlier this month when Tameside introduced wider social distancing restrictions.

“It is cruel,” she said. “The staff come and go every day and yet we are not allowed even socially distanced garden visits.”

Nadra Ahmed, executive chairman of the National Care Association, said some operators still wanted to enable end-of-life visits and allow a nominated regular visitor to be tested as part of the staff group.

But, she said, “people are terrified they are going to get blamed for transmission”.

On Monday Labour called on the government to set out a fresh strategy to protect care homes this winter, including treating families as key workers to give them access to care homes.

Liz Kendall, the shadow care minster, told the health secretary, Matt Hancock, in a letter: “We cannot afford for action to protect care homes and other services to be as slow and chaotic as it was at the start of this pandemic.”

Some homes have spent large sums to make visiting possible, including installing fogging machines to disinfect visitor rooms and unmanned thermal imaging machines to scan visitors’ temperatures.

Nicola Richards, who runs three homes in Sheffield, has installed a £20,000 visitor pod at one home. It has a screen down the middle and an intercom. Her homes have only been allowing visits at widows and inside the home only at the end of life.

“We are monitoring the uptick in infection and it is a possibility that in the near future visits may have to be restricted again, where necessary to protect our residents,” said Dan Hayes, chief executive of the Orders of St John. Testing of his staff showed less than half a per cent were infected, but there has been a small increase recently. He said: “Our focus had been on looking to expand visits, but we sadly have to consider the opposite if and when circumstances dictate we should.”

Raj Seghal, who runs four homes around Kings Lynn, Norfolk, said: “It is going to become more and more difficult and we have to watch the local infection rates. If we are heading towards a peak we may have to cancel the visits.”

The Department for Health and Social Care has been contacted for comment.