title: Transmission of hepatitis B associated with hemodialysis: role of malfunction (blood leaks) in dialysis machines.
abstract: In the first 10 months of 1974, 26 of 60 susceptible patients in a commercial hemodialysis unit developed asymptomatic infection with hepatitis B virus; 17 (65%) of the 26 cases occurred in 14 weeks from July to October. In a case-control study, 15 of 16 cases for whom records were available were found to be associated with malfunctions of dialysis machines (primarily leaks or ruptures in dialysis membranes) that had occurred before patients converted to hepatitis B surface antigen (HBs Ag) positivity. In comparison, 17 of 34 controls were associated with machine malfunctions (P less than 0.01). In addition, the mean number of malfunctions in machines per patient was significantly greater for cases of infection (2.25 +/- 1.34) than for controls (1.06 +/- 1.39) (P less than 0.01). Furthermore, a direct correlation was demonstrated between an increase in blood leaks in machines used with susceptible patients and subsequent increases in cases of hepatitis for the various beds in the unit (r=0.994, P less than 0.0001). The mean period from the last blood leak to HBs Ag seroconversion was 67 days. Six of the 36 blood leaks associated with cases of infection occurred less than 6 hr after leaks in the contaminated area, whereas only one of 36 leaks associated with controls demonstrated this relationship (P less than 0.05). These data suggest that the conversion to HBs Ag positivity was linked to the occurrence of machine malfunctions (blood leaks) and that events which occurred during these episodes caused the spread of infection.
mesh_terms: D006509:Hepatitis B / Q000150:complications / Q000635:transmission*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications; D008567:Membranes, Artificial; D006435:Renal Dialysis / Q000009:adverse effects*; D013997:Time Factors
chemical_list: D008567:Membranes, Artificial