The helpline set up at Beaumont Hospital to deal with the issue of potential CJD infection from surgical instruments has said that 13 hundred people contacted the service yesterday.
All patients, who may have contracted the brain disease from contaminated instruments, have now been contacted by the health service.
Up to 20 people may have been exposed - after operating equipment used on a patient with CJD was used on other people in recent weeks.
The phone line opened at 8pm yesterday morning, and a spokesman said they were able to reassure most patients that they were not at risk.
The Chairman of the Irish Patients Association, Steve McMahon, said that it would be an incredibly challenging time for anyone told they are at risk of CJD.
"Clearly their rights are that care, attention and support would be given to them by the system," he said.
"And indeed in may be that some of them may choose to go down a legal route because of this impact on them."