A further 100 patients at Dublin's Beaumont Hospital were today waiting to find out whether they are infected with the winter vomiting bug.
As the outbreak - which began two weeks ago - continued to escalate it was confirmed that 24 patients had tested positive for the virus.
The illness has seriously disrupted the hospital, with about a sixth of beds unavailable and new admissions being diverted to other hospitals.
A spokesman for the hospital said in addition to the 24 confirmed cases, the number of suspected cases among patients stood at 101.
In addition, some 50 staff have displayed symptoms over the two weeks. Of the hospital's 19 wards, 16 remained unavailable to new admissions because of the presence of the virus, and about 110 beds were closed out of a total of 630, he confirmed.
Ms Maureen Brown of the Eastern Regional Health Authority said Beaumont was hoping to reopen one of the closed wards during the day.
The hospital is urging members of the general public to stay away unless their visit is essential.
Yesterday both Mater Hospital and James Connolly Hospital cancelled non-emergency operations in order to help free up beds at Beaumont.
PA