Four hospitals in Dublin are under pressure from an outbreak of the winter vomiting bug and are asking people not to attend accident and emergency departments if they believe they are suffering from the virus.
The Eastern Regional Health Authority (ERHA) is reminding patients that the virus, which causes vomitting and diarrhoea, generally last 24 hours but if symptoms are prolonged a local GP should contacted first.
ERHA director of public health Dr Marie Laffoy said although the virus is in the community - particularly on the southside of Dublin - reporting to hospitals is likely to increase its spread.
She advises sufferers to drink plenty of fluids and wash their hands frequently to prevent spreading the infection. Two days rest from work or school should be taken after the symptoms clear up, Dr Laffoy added.
Services at St Vincent's hospital and St James's hospital on the southside and Beaumont hospital on the northside are under pressure because of the outbreak.
St Vincent's has over 50 cases affecting ten wards; three wards at St James's have been affected, and Beaumont hospital has reported an outbreak in one of its wards. Tallaght Hospital has not been affected.