A case of TB has been confirmed at the private St Columba's College in Rathfarnham, Dublin.
Yesterday, the health authorities sent a letter to parents advising them of the situation, and reassuring them that the disease is not highly infectious.
A male domestic worker at the co-educational boarding school contracted the disease, and is now in Peamount Hospital.
A spokeswoman for St Columba's said the 300-pupil school had not been closed but any advice from the health board would be followed. The East Coast Area Health Board is investigating the case, and is determining the potential risk to staff and pupils.
A health board spokesman said parents were being told that TB was not a highly infectious disease, and that it could only be transmitted through a significant amount of close, personal contact.
He said the board was now implementing public health control measures. These involved "contact tracing", where health officials determined if anyone had been in close contact with the infected person. If anyone was found to be at risk, they would be tested.
The school was on a mid-term break earlier this week, and the spokeswoman said most people were not aware of the case.
According to the National Disease Surveillance Centre, the incidence of TB has declined steadily since the early 1950s, when there were nearly 7,000 cases a year in the State. However, more than 400 cases are still notified in Ireland each year. Doctors are obliged to notify each one to the department of public health in the local health board.
The disease is completely curable, with tablets taken for about six months to clear the infection. Newborn babies receive the BCG vaccine to protect them from TB. It is also given to adults who are considered to be at risk of developing the disease.
According to the National Disease Surveillance Centre, the disease is usually spread in the air from another person who has TB of the lungs. Only some people with TB in the lungs are infectious and even then close contact with such a person would be needed.
Symptoms can include fever, night sweats, coughing, weight loss or blood in phlegm.
Meanwhile, Scotland is experiencing a TB scare, following the death of a college lecturer last week. Mr Peter Allan, (39) who lectured at Dundee College, died from pulmonary tuberculosis.
More than 400 people who came into close contact with him have been offered screening.
