A probable case of Legionnaires' disease was identified yesterday in the east of the country, The Irish Times has learned.
It is believed that six other people are suspected of having the infection, although the usual investigation of the outbreak has been hampered by a work-to-rule by public health doctors.
The industrial action means that public health specialists in both the National Disease Surveillance Centre (NDSC) and the regional health boards are unavailable this weekend to manage the outbreak.
Legionnaires' disease is caused by a bacterium - Legionnella Pneumoniae - which grows in stagnant water.
Previous outbreaks have been associated with cooling systems in hotels and office blocks and jacuzzis in leisure centres.
The disease was first identified in the US in 1976 when American Legionnaires attending a reunion in a hotel in Philadelphia became ill with pneumonia.
Sources have claimed that the doctors' industrial action, which was initiated because of a nine-year grievance over non-payment for weekend and out-of-hours work, will delay the investigation into the source of the bug. It will also hamper the search for other people who may have been exposed to the same source.