The Centre for Health Protection is investigating a case of Legionnaires' disease involving a 57-year-old woman who is in stable condition.
She fell ill on October 20 and was admitted to Princess Margaret Hospital on October 24.
Tests revealed that she was suffering from Legionnaires' disease.
This is the 32nd case of the disease reported to health authorities this year.
There were 28 cases both in 2013 and 2012.