At least 1,300 people have contacted a Health Service Executive helpline set up today to provide information to people concerned about the possible spread of a degenerative brain disease at Beaumont Hospital.

Up to 20 people who were operated on with medical instruments previously used on a patient with Creutzfeldt-Jakob Disease (CJD) will be contacted by the end of today.

The HSE said the patient had recently been diagnosed with CJD in Beaumont Hospital and that the family have requested privacy at this time.

Assistant national director of health protection at the HSE Dr Kevin Kelleher said the people operated on with the same instruments as the person with CJD will now be at a slightly higher risk of contracting the disease than the general population.

About one in a million people a year get CJD in Ireland; the risk to those who have been exposed to contaminated instruments is “slightly above that”, Mr Kelleher told RTÉ’s Morning Ireland.

He said there has not been a recorded example of a patient contracting the disease in those circumstances in the past thirty years.

But is understood the patients will require long term monitoring, possibly for the rest of their lives, to determine whether they have the fatal disease.

Minister for Health James Reilly expressed concern about the incident and said he would be seeking reassurances from the HSE and the hospital that the protocols in place to prevent a re-occurrence were sufficient.

But Dr Reilly said there was no “clinical suspicion” or anything else to suggest a case of CJD was involved at the time the patient was operated on. Later, during a “routine” biopsy examination, doctors became suspicious and tests were carried out. However, these took some time to complete.

“As soon as they realised this was a diagnosis of CJD all actions were taken,” Dr Reilly said, speaking today at an event in the Blackrock Clinic.

Taoiseach Enda Kenny offered his sympathy to the patient initially diagnosed with CJD and said an expert panel had been set up to investigate the risks posed to those who underwent surgery with the affected equipment.

“I hope that the expert panel set up will follow through on the process and will be able to come through with full information for anybody who might have come into contact,” Mr Kenny said. “In respect to the risk, which I understand to be very low, it may be necessary to have regular assessments of those people throughout their lives.”

The chairman of the Irish Patients Association Stephen McMahon said there seems to have been an “information deficit” at Beaumont. “We still don’t know whether it is 10 or 20 [patients affected]” he said, adding that “there obviously would have to be a serious incident review”. He also said the patients might “very likely” seek legal compensation.

In a statement this evening, the HSE said the exact number of patients involved would not be made public in order to protect patient confidentiality.

If instruments are used on a patient with CJD, international guidelines say they must be put through a special highly rigorous sterilisation procedure or destroyed because normal sterilisation techniques are not sufficient.

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

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

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. Creutzfeldt-Jakob Disease (CJD) is a rare illness and is one of a group of diseases called prion diseases, which affect humans and animals.

Prion diseases exist in different forms, all of which are progressive, currently untreatable and ultimately fatal.

The risk of CJD increases with age, and in persons aged over 50 years of age, the annual rate here is approximately one case per million.CJD is a notifiable disease and with small numbers of cases of CJD in Ireland 30 cases reported between 2005 and 2011.

A new form of CJD (variant CJD) linked to bovine spongiform encephalopathy (BSE) in cattle was identified in 1996. Four cases of vCJD in total have been identified in Ireland to date.