Two women who underwent double lung transplants died after contracting a bacterial infection linked to a contaminated water supply at a hospital, an inquest heard.

Royal Papworth Hospital was relocated to a new site in Cambridge in May 2019, and in August 2019 two patients tested positive for Mycobacterium abscessus during routine testing.

Before the specialist heart and lung hospital opened at its new site, the water supply had been deemed clean and safe and the hospital was approved for occupation.

The hospital launched an investigation and water sampling in November 2019 confirmed that the bacteria was in the water supply, the hospital said on its website.

Its chief executive said “immediate action” was taken to ensure patient safety.

Karen Starling, 54, of Ipswich, Suffolk, died on February 7 2020 and 65-year-old teacher Anne Martinez, of Borehamwood, Hertfordshire, died on December 17 2020, both at the hospital.

The hospital said on its website that it is “likely” 34 patients who tested positive for the bacteria were “related to the outbreak”.

“Many patients have not needed treatment to date, and several have now tested negative after one positive result,” the hospital said on its website.

Keith Morton, assistant coroner for Cambridgeshire and Peterborough, found that Mrs Starling and Mrs Martinez’s M. abscessus was a hospital-acquired infection.

At an inquest, which concluded in Peterborough on Friday, the coroner said he would write to the Department of Health and Social Care about concerns he had over a lack of guidance to hospitals around identifying and controlling the bacteria.

In a joint statement, Mrs Martinez’s sons Anthony, 40, and 35-year-old Andrew said: “We will never get over losing mum and particularly in the way we did.

“We would do anything to have her in our lives, but we know that’s not possible.

“All we can hope for now is that others don’t have to go through the hurt and pain we continue to live with.”

Mrs Starling’s husband Derek said it “felt like she had a new lease of life” after her transplant and she “stopped using the stairlift and was able to walk round the shops once more”.

But once they were told about her infection “everything seemed to change”.

“We were all praying she would pull through but she couldn’t because of her weakened immune system,” he said.

Eilish Midlane, chief executive of Royal Papworth Hospital NHS Foundation Trust, said: “The deaths of Mrs Martinez and Mrs Starling have been devastating for their families.

“We send our heartfelt condolences to them and are terribly sorry for their loss.

“While the coroner acknowledged that we had followed national guidance in place at the time for the testing and management of water safety, we are grateful for the opportunity to review the findings in full so that any further learning is embedded and shared.

“We launched an investigation as soon as this issue was identified in 2019 and took immediate action to ensure patient safety, including installing specialist filters on taps and showers and enhanced treatment of the water supply, which regular testing shows has remained effective.”

Jennifer Hodgson, the specialist public health lawyer at Irwin Mitchell representing the families, said: “Karen and Anne were hopeful that their transplants would greatly improve their quality of life.

“While the surgical care they received isn’t in question, the events that unfolded afterwards have had a devastating effect.

“While nothing can make up for their loss, we’re pleased that we’ve at least been able to secure the answers Karen and Anne’s families deserved.”

She added it was “vital that all lessons possible are learned, to reduce the risk of a similar outbreak happening again”.