Beaumont Hospital in Dublin has confirmed that a patient has recently been diagnosed with Creutzfeldt-Jakob Disease (CJD) and the hospital is now working to assess 'if any risk may exist for other patients'.

The infection was discovered in a patient undergoing surgery at the hospital.

It is believed that between 10 and 20 patients may be affected. Any affected patients are expected to be contacted by the HSE later today. The HSE says the risk of infection is very low.

CJD is known as a prion disease, which means it can affect both humans and animals. It is a very rare form of dementia and tends to affect people between the ages of 50 and 80. However in the 1990s, a new variant (vCJD) of the disease was identified, which affects people at a much younger age. Research indicates that vCJD is caused by cross infection from cattle with BSE (mad cow disease), in other words, it is contracted through eating infected meat.

According to the HSE, 'prion diseases exist in different forms, all of which are progressive, currently untreatable and ultimately fatal'. The disease is notifiable and the annual rate here is one per million of the population. In 2011, seven cases were notified, while in 2010, three cases were.

As the disease can be passed on via contaminated surgical instruments, the HSE emphasised that when a case of CJD is diagnosed, 'a review is undertaken to ensure that any precautions, if needed, are taken, in line with the National and International Guidance'.

Normal sterilisation procedures are not sufficient to destroy CJD on surgical instruments. They must either be destroyed or undergo a specialist sterilisation technique. Concern has now been raised that some of the instruments used on the patient diagnosed with CJD may have been used on other patients before the diagnosis was made.

Beaumont has been checking medical records to see exactly how many patients were operated on using instruments that were used on the patient diagnosed with CJD.

Health Minister James Reilly has said he was very concerned about the developments. He said there had been no suspicion that the patient had CJD and it only emerged during a routine biopsy examination.

Dr Reilly said that once CJD was identified all necessary actions were taken.

The HSE said there is a very low risk of infection, but any patients who might be affected would be monitored to see if they developed any symptoms.

Beaumont is receiving advice from the Irish Panel on TSE (CJD) and from world experts in the UK who have dealt with similar issues worldwide.

"This group is assessing the circumstances of this case to determine what, if any, risk may exist for other patients. Further information will be available once this group has completed its assessment."

"The primary concern of Beaumont Hospital is for its patients and their care. Until the necessary risk assessment is completed and the necessary contact made with patients, it is not in a position to discuss the issues under review," the hospital stated.

It added that while the number of potential patients affected is low and is confined to one area of surgery, it has now opened a helpline to respond to any concerns. The number is 1800 302 602.