Air-rinsing after dialysis. A mode of transmission of hepatitis virus.

During a recent outbreak of hepatitis B among patients receiving dialysis, georgraphic and temporal distribution of cases in the absence of exposure to blood products suggested patient-to-patient transmission. The patients who contracted hepatitis used Kiil dialyzers with a single-pass dialysate system, while patients who used hollow-fiber dialyzers appeared to be protected. Blood was returned to patients after Kiil dialysis by the air-rinse technique with the use of a nonsterile plastic tube attached to a manometer bulb. Laboratory experiments demonstrated that Staphylococcus aureus and poliovirus became widely distributed throughout the Kiil dialyzer when introduced during the rinse phase by contaminating the air-rinse tubing.