Two fresh samples of the Legionnaires' bacteria have been found in the Waterford hospital where a woman died of the disease earlier this month.
The traces were discovered on a shower unit and a tap in different parts of Waterford Regional Hospital, according to a statement from the South Eastern Health Board.
The dead woman had been treated in the hospital when she contracted the disease, but no further cases have yet been identified.
Following the death, samples were taken last week from more than 100 sites around the hospital, including taps and showerheads, under guidelines put in place by the Irish National Disease Surveillance Centre.
The SEHB said the results from the first batch of 38 samples showed the presence of the legionella bacteria in one sample, and results from a subsequent batch had indicated presence of the bacteria in one more sample to date.
The Health Board said the results were not unexpected because legionella was a naturally occurring bacterium in water.
The hospital shower unit and tap, which showed up a presence of legionella, were replaced and patients moved as a precautionary measure.