Polymicrobial outbreak of intermittent peritoneal dialysis peritonitis during external wall renovation at a dialysis center

. Objective:To investigate an outbreak of peritonitis in intermittent perit oneal dialysis (IPD) patients. . Design: An outbreak investigation was performed to identify the etiology of the polymicrobial outbreak, and a retrospective case-control study was c onducted to assess the risk factors for development of peritonitis. . Setting: Renal dialysis center. . Patients:Ten episodes of peritonitis occurred in 8 of 61 patients over a 6-month period in which 669 IPD procedures were analyzed. . Interventions: Field visit to renal dialysis center to examine the entire IPD procedure, inspect the hospital environment, and perform air bacterial count. . Main Outcome Measures: The environmental factors and risk factors contrib uting to the polymicrobial peritonitis outbreak in IPD patients. The incide nce of IPD peritonitis was determined before and after interventions. . Results:The causative organisms included Acinetobacter baumanii (6), Sten otrophomonas maltophilia (2), Pseudomonas aeruginosa (1), Candida albicans (1), C. tropicalis(1), Enterococcus(3), and Enterobacteriaceae (2). Four ep isodes of peritonitis involved infection by more than one organism. Air sam pling of the environment detected a median of 110 colony forming units of b acteria per cubic meter of air, 10% of which were found to be Acinetobacter baumanii. The source of this polymicrobial outbreak was attributed to the bamboo scaffolding structure covering the external wall of the hospital dur ing renovation. A retrospective case-control study indicated that the absen ce of the flush-before-fill step was a risk factor for development of perit onitis. . Conclusion: In addition to invasive aspergillosis in transplant or oncolo gy patients, Acinetobacter peritonitis in dialysis patients should be consi dered another microbial cause of outbreak associated with hospital renovati on.