There has been an outbreak of the vomiting bug at the Louth County Hospital in Dundalk.
As a result of the outbreak visitor restrictions have been put in place at the step down ward of the hospital.
People are asked not to visit patients for the foreseeable future in order to prevent the bug from spreading.
A statement from the HSE said: “Visitor restrictions have been introduced with immediate effect on the step down ward at Louth County Hospital due to an outbreak of norovirus – commonly known as the vomiting bug. This is in the interest of patient care and in order to curb the spread of the vomiting bug within the hospital.
“In so far as possible the public are asked to avoid visiting the step down ward. Visits to the ward are at the discretion and prior arrangement by the Nurse in Charge.
“Visitors are also requested to cooperate with hospital staff who are ensuring the restrictions are adhered to and visitors are also advised that they must use the alcohol hand gels supplied as they enter and leave the hospital.
“The public are requested not to visit the hospital if they have been affected by vomiting and/or diarrhoea, or if they have been in contact with anyone with these symptoms until they have been symptom free for 72 hours.”