The first victim of hospital-acquired coronavirus in the UK has been identified in a development that has fuelled concerns the disease is spreading within hospitals.

Marita Edwards, a retired cleaner and keen golfer, went to Newport’s Royal Gwent hospital for a routine gallbladder operation on 28 February.

The otherwise fit 80-year-old then caught an infection in hospital that she and her family were initially told was pneumonia. Last Thursday, almost three weeks after arriving at the hospital, she tested positive for Covid-19 and died the following day.

Facebook Twitter Pinterest Marita Edwards. Photograph: Stuart Loud

“If she had not been in hospital she would be still be alive,” said her son, Stuart Loud. “Clearly there was a coronavirus infection in the hospital which claimed my mum’s life.”

Edwards, who had a son, daughter and granddaughter, was one of five patients to die in Royal Gwent last weekend out of a total of 16 coronavirus deaths so far in Wales.

Her death raises questions about the hospital’s failure to test earlier for the disease and what precautions it took to curb its spread among patients and staff. The Aneurin Bevan University Health Board, which runs the hospital, declined to answer questions about Edwards’ treatment, and referred the Guardian to Public Health Wales (PHW).

It said it could not comment on individual cases or hospitals. It also refused to say how many patients have died as result of hospital-acquired coronavirus in Wales.

A PHW spokesman said: “We have a responsibility to protect individuals tested and patients being treated for coronavirus. For this reason we will not share any information on these individuals other than that published in our official statements.”

Dr John Ashton, a former regional director of Public Health England, said: “Hospitals themselves are becoming sources of infection and threaten to be the centre of the epidemic. They are becoming unsafe places for people who haven’t got the virus, whether they are NHS workers or patients.”

He added: “It will be better for people to stay at home. There will not be anywhere enough intensive beds and meanwhile anybody in the hospital environment will be at risk of infection as with Ebola in west Africa. We should switch to supporting the community to nurse its own mostly at home and use clinical skills for skill transfer to lay carers.”

Loud described his mother, who lived in Bulwark in Monmouthshire, as a “very fit lady” who regularly played nine holes of golf, before being going into hospital for the operation.

He questioned why she was not tested for coronavirus earlier, and why she was then not treated on a ventilator.

He said: “Doctors afterwards were absolutely beside themselves that this had happened so quickly and that they didn’t pick it up earlier … The leadership of the clinical team should have questioned how this was allowed to develop at that late stage without testing.”

Loud, 50, a packaging supply manager from Westbury, in Wiltshire, added: “I do feel there was a ventilator lottery with my mum. I think bets were hedged on whether younger people might be infected and would need that equipment. The fact that my mum was 80 was probably not in her favour. I don’t think the resources are there, and the medical profession isn’t quite ready for this.”

Until last week, Edwards was allowed to be seen by hospital visitors in the normal way, her son said.

Loud added: “Once they had suspicions that there might be the corona, they isolated the ward. We then had to go through a protocol every time we entered with masks, gloves and aprons. We couldn’t hug her or kiss her. We couldn’t hold hands. We took it in turn to sit with her and hold a mask to her face. She died the most horrific death. I don’t want anyone else to have to go through what our family is going through right now.”