Three hospitals in the south-east are now affected by suspected cases of the so-called winter vomiting virus. A total of 34 patients and 12 members of staff at the 101-bed Sacred Heart Hospital in Carlow are believed to have contracted the virus.
The hospital remains closed to visitors and admissions have been curtailed to curb the spread of the suspected virus. At St Dympna's Hospital, Carlow, there have been six suspected cases of the virus since the weekend.
The long-stay wards at the hospital have been closed to visitors.
The South Eastern Health Board is also urging people not to visit St Luke's Hospital, Kilkenny, after a suspected cases of the virus there.
Six patients are currently in isolation and one member of staff is off duty having displayed symptoms of the virus. Some elective admissions have been deferred due to the suspected outbreak.
The public are being asked not to go to the hospital unless it is absolutely necessary.