Outbreak of Pseudomonas aeruginosa infections after transrectal ultrasound-guided prostate biopsy

After the Georgia Department of Human Resources Division of Public Health was notified about 4 patients who were hospitalized with Pseudomonas aeruginosa infections after outpatient transrectal ultrasound-guided prostate biopsies in July 2005, we investigated the cause of, and risk factors for, the infections.

We enhanced surveillance for additional cases, reviewed medical records, evaluated biopsy equipment and infection control practices, and collected environmental samples. Transrectal ultrasound-guided prostate biopsy procedures were discontinued during the investigation.

A total of 4 cases were identified. All patients were men aged 57 to 71 years. All 4 recovered with antimicrobial therapy. P. aeruginosa was isolated from the narrow lumen of the steel biopsy needle guide that had been soaking in high-level disinfectant for several days. The needle guide isolate and three available clinical isolates were indistinguishable by pulsed-field gel electrophoresis. A review of the reprocessing procedures of the biopsy needle guide revealed that it was disinfected by submersion in high-level disinfectant rather than sterilization, the reprocessing procedure recommended by the manufacturer. Manual cleaning of the lumen was limited to flushing. After disinfection, the guide was rinsed with nonsterile tap water.

The outbreak resulted from a contaminated needle guide. The needle guide reprocessing procedures were inadequate. Potential causes of P. aeruginosa contamination include the lack of adequate manual cleaning before disinfection, failure to sterilize the needle guide, and the use of a tap-water rinse after disinfection. Clinicians performing transrectal ultrasound-guided prostate biopsy procedures should follow the manufacturers' needle guide reprocessing recommendations or use disposable needle guides.