OUTBREAK OF NOSOCOMIAL URINARY-TRACT INFECTIONS DUE TO PSEUDOMONAS-AERUGINOSA IN A PEDIATRIC SURGICAL UNIT ASSOCIATED WITH TAP-WATER CONTAMINATION

An outbreak of 14 cases of urinary tract infections by Pseudomonas aer uginosa, including six symptomatic infections, occurred from September to November 1994 in a paediatric surgical unit. During the outbreak, urine samples from patients and multiple samples from the environment of patients were tested for the presence of P. aeruginosa. Bacterial i solates were studied by pulsed-field gel electrophoresis. Genotypic an alysis showed that most of the isolates from children were different. Multiple P. aeruginosa isolates were also found in the tap water, as t he only putative source of contamination. Two of these isolates were i dentified in two infected patients, indicating possible direct contami nation of patients via tap water and this was related to the distal co lonization of faucets. Bacteria were eradicated from tap water by repl acement of taps. The cluster of cases of P. aeruginosa urinary infecti on was, therefore, related to multiple contaminations through tap wate r. These results illustrate an unexpected risk of nosocomial infection and emphasizes the importance of checking tap water to prevent bacter ial contamination through handwashing in contaminated water.