Prolonged outbreak of nosocomial urinary tract infection with a single strain of Pseudomonas aeruginosa.

Sixty-six hospitalized patients became infected with a single strain of multiply resistant Pseudomonas aeruginosa over a 22-month period. The catheterized urinary tract was the site of the infection in 59 patients (89%). The outbreak was confined to a urology ward until an infected patient from this ward spent 2 weeks in the surgical intensive care unit (SICU). Subsequently patients who acquired the infection in the SICU were discharged to surgical wards throughout the hospital. Urine measuring containers and urometers used in the SICU were the reservoir of the P. aeruginosa; daily sterilization of this equipment terminated the outbreak. Urometers appeared to be the reservoir of the epidemic strain in subsequent outbreaks. Five patients were still infected when they were readmitted 3 to 12 months after the first admission, and therefore represented an additional reservoir of infection.