A case of Legionnaires' Disease in Tallaght, Dublin, has been notified to the National Disease Surveillance Centre.
A man in his thirties is being treated for the disease at Tallaght General Hospital. It emerged at the weekend he had been admitted to another hospital a couple of weeks ago and was later transferred to the intensive care unit at Tallaght.
His condition was described as critical, although the hospital is expected to provide an update later today.
The hospital confirmed last night the man had contracted Legionnaires' outside the hospital. It's believed the man's residence has been fumigated and isolated while an investigation takes place.
The National Disease Surveillance Centre (NDSC) confirmed this morning that it had been notified of the man's condition, as is required by law for certain diseases. It is believed the case is an isolated one.
Legionnaires' Disease is usually contracted through the respiratory tract by inhalation of contaminated water through infected plumbing systems.
The NDSC believes there may be a "major degree" of under-diagnosis of legionellosis, which can present as either Legionnaires' Disease (LD) or Pontiac fever.
Anyone can develop LD, but the elderly, cigarette smokers, heavy drinkers, people with chronic lung conditions or those with depleted immune systems are particularly at risk. Most cases are sporadic, or isolated, while about 10 to 20 per cent are linked to outbreaks. The condition has 'flu-like symptoms and can be fatal.
The NDSC says greater attention should be given to the notification of LD in order to identify potentially preventable transmission of the disease.