Two reports have been published into the death of a woman who contracted hepatitis B while in hospital last year.
Nancy Lane, 68, from Aberaman died after contracting the infection following a heart operation at Morriston Hospital in March 2011.
The first report, by an Independent External Review Panel, concluded that it was not possible to identify "a single event" that had led to infection.
It was most likely, the report said, that the hepatitis virus was transmitted by a Transoesophageal echocardiography (TOE) probe, which would have been used to visualise the heart.
Mrs Lane's family said her death remained "a terrible loss", and issued a statement calling for the report's recommendations to implemented in full
The second report was compiled by the Public Health Wales Nurse Consultant for the Welsh Healthcare Associated Infection Programme Team Dr Neil Wigglesworth, after a visit to the Cardiology and Cardiothoracic departments in January 2012.
It found "significant improvements" in decontamination of medical equipment, and said there was "evidence of good quality, safe and effective processes for infection prevention and control, equipment decontamination and environmental hygiene"