Clustered bacteremias in a hemodialysis unit: cross-contamination of blood tubing from ultrafiltrate waste.

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.