Patients operated on with unsterilised instruments

Twenty-one hospital patients were subjected to treatment using unsterilised surgical tools - and not told of the blunder for almost three weeks.

Now Aneurin Bevan health board has apologised for the mistake which involved operations and examinations on 25 and 26 of February. It said the risk was extremely low but it had arranged testing as a precaution.

On 24 February, the instruments were disinfected, but not sterilised.

The tools were then used at Newport's Royal Gwent Hospital, leading to a risk of blood-borne viruses being transmitted. The mistake was discovered during a routine check on 27 February.

But Aneurin Bevan health board did not contact patients until 16 March.

A spokesman said: "We have already contacted the patients affected and want to offer our sincere and heartfelt apologies for the worry this situation may cause.

"While the clinical risk of blood-borne virus exposure is extremely low, we have arranged precautionary testing and support to give full reassurance."

The failure is being investigated the health board said: "We fully recognise the concern and distress this may cause, and we are truly sorry.

"The wellbeing of our patients is our highest priority, and we are taking all necessary actions to understand how this happened and to prevent it from occurring again.

"We also understand that others may feel concerned on hearing about this. We want to reassure all patients that this was a very limited incident, those affected have been contacted directly, and there is no wider cause for concern."

The Welsh government said it was aware of a patient safety matter at the hospital.

It said it had been told affected patients were being supported and there was no evidence of wider impact.

A spokesperson added: "We have been assured the health board is taking all precautionary measures to prevent incidents like this from happening again."

Llais, which represents people across health and social care in Wales, said the public needed to know processes to protect them were being followed and working.

People, it said, would be understandably worried unsterilised instruments were used, and patients waited to be told.

A spokesperson said: "Health boards have a duty to keep people safe and, in line with the duty of candour, to be open and take prompt action when things go wrong."

They added: "It's essential for trust and confidence that the investigation is thorough and that learning leads to real change."

Plaid Cymru dubbed the failings "terrifying".

It said: "Those responsible for such glaring failings on clinical safety should be brought to account - and the health board must show full transparency on how it is dealing with this."

The Welsh Conservative's health spokesman Peter Fox called it "a serious breach of care."

"An apology alone is not good enough. We need a full investigation into why this appalling incident occurred."

Reform's Laura Anne Jones, said: "It's scandalous that it's taken three weeks for my constituents to be informed."

The Welsh Liberal Democrats and the Green Party have been approached for comment.