The Health Minister says there was no clinical suspicion that a patient at Dublin's Beaumont Hospital was suffering from CJD.

Around 20 other people could be at risk of contracting the brain disease - because medical instruments used on the CJD patient did not undergo special sterilisation.

The Health Service Executive is today making contact with those who may have been exposed to the degenerative condition.

James Reilly says the incident is a matter of concern and he is seeking reassurances that the protocols in place are sufficient.

CJD, or Creutzfeldt-Jakob's Disease, is very rare, currently untreatable, and ultimately fatal. It can be passed from patient to patient through contaminated instruments.

The HSE last night confirmed a patient at the hospital was diagnosed with the fatal degenerative brain disease - the first case detected in Ireland since 2011.

However, a number of cases of the disease - which causes dementia - were found most years for the last 9 years.

Health chiefs are now checking medical records to determine how many other patients were operated on using instruments which had been used on this patient. It is understood the patient with CJD was operated on 2 weeks before the diagnosis. The patient's family has requested privacy.

Head of Health Protection at the HSE Kevin Kelleher told Newstalk Breakfast this morning that the risk of anyone else getting the disease is low - but those affected will have to be monitored for the rest of their lives.

Prof. John Collinge from the NHS in the UK explains what CJD is and what happens. It is not clear which type of CJD the patient in Beaumont Hospital has.

Beaumont Hospital has issued a statement this morning, to say it is receiving advice from the Irish Panel on 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. Further information will be available once this group has completed its assessment.

Hospital authorities at Beaumont say their primary concern is for patients, and their care. Until the necessary risk assessment is completed and the necessary contact made with patients, chiefs will not discuss the issues under review.

They add that the number of patients potentially affected is low and confined to 1 area of surgery. A helpline has been set up at 1800-302-602