Wexford General Hospital has closed its doors to visitors today after it revealed that twelve patients and eight members of staff have contracted the Winter Vomiting Bug.
The outbreak began last week, and on Friday, three medical wards were closed in a bid to confine the infection.
Theresa Hanrahan is Hospital Manager at Wexford General.
She says the bug is highly infectious.
"We are closing the hospital for victors unless it's absolutely essential because trying to confine it as much as possible," she said.
"If there is a new case today, it'll mean there will be a danger of other people getting it for the next 72 hours. So that will mean Thursday."