A patient in St Luke's General Hospital in Kilkenny has been diagnosed with Legionnaires' disease, The Irish Times has learned.
It is understood that an elderly man was admitted to the hospital on Tuesday last complaining of a dry cough and shortness of breath.
A chest X-ray confirmed the presence of an atypical pneumonia.
Following further investigation, a test for legionella pneumophilae, the bug that causes Legionnaires' disease, was found to be positive.
The man, who is from the area, was commenced on antibiotics and has responded well to treatment.
According to a reliable source, the man has received a kidney transplant in the past.
Such patients must take immune system suppressant drugs - to minimise the risk of organ rejection - and are prone to unusual infections such as legionnaires'.
As the man was admitted to the hospital with pneumonia, it is considered likely that he contracted the disease in the community. The incubation period for legionnaires' disease is two to 10 days.
The first ever proven case of hospital-acquired Legionnaires' disease in the Republic occurred in Waterford Regional Hospital last April.
The case precipitated a major review of hospital infrastructure within the South Eastern Health Board (SEHB), after investigations revealed that a shower in the patient's room was the source of the bacteria. In a statement confirming the latest case, a spokeswoman for the SEHB said: "environmental and community-based testing has been carried out and we are awaiting detailed results.
"There are no indications yet as to where the infection was acquired."
Since the Waterford case, the SEHB has introduced protocols for testing water sources for the bacteria as well as the regular flushing of taps and showers.
It has recently spent €100,000 on new water tanks in St Luke's.