The Centre for Health Protection is investigating a case of Legionnaires' disease involving a 60-year-old man.
He fell ill on April 15 and was transferred from a private hospital to another facility yesterday. He was diagnosed as having pneumonia and is now in serious condition.
Tests revealed he was suffering from Legionnaires' disease.
The patient had no travel history and his home contact has no symptoms.
It is the 10th case reported this year. There were 41 cases last year and 28 cases in 2013.
