Brief Report: Clustered Bacteremias in a Hemodialysis Unit: Cross-Contamination of Blood Tubing from Ultrafiltrate Waste

Abstract

Objective: To determine the cause of clustered bacteremias occurring among chronic hemodialysis patients. Design: A retrospective investigation of clinical and laboratory records with direct observation of dialysis facilities and technique. Bacterial blood isolates were identified and compared with environmental isolates. Setting: The 11-station chronic hemodialysis unit that serves approximately 50 patients in a 450-bed military hospital. Patients: Hemodialysis unit patients with aerobic gram-negative bacillus or Enterococcus casseliflavus blood isolates between April 1988 and February 1990. Results: The recovery and species identification of the unique isolate, E casseliflavus, from 2 index cases of bacteremia in February 1990 helped identify the cluster and demonstrated its protracted course. Dialysis blood tubing was contaminated with ultrafiltrate waste during dialyzer setup. Intervention: Bacteremias were controlled by halting the practice of attaching the venous tubing directly to a waste container while priming the membrane, by emphasizing glove changes and handwashing after contact with ultrafiltrate waste and by daily decontamination of ultrafiltrate waste bags. Conclusions: We recommend that other hemodialysis units institute these interventions.