Resolution of a Pseudomonas aeruginosa outbreak in a hematology unit with the use of disposable sterile water filters.

We observed a significant increase of Pseudomonas aeruginosa bacteremias during 2002. Eighty-five microbiological samples were taken from different potential sources of infection. Twenty-nine out of 46 specimens obtained from water taps, shower heads and siphons tested positive for Pseudomonas aeruginosa. Weekly pharyngeal and rectal swabs in high risk patients, use of tap water after running the tap for at least 5 minutes and use of weekly disposable sterile filters in all taps and showers resulted in a significant decrease in Pseudomonas aeruginosa bacteremias. Moreover, we observed a significant reduction in Pseudomonas aeruginosa-positive surveillance cultures after implementation of these measures.