Occasional infection of hepatitis C virus occurring in haemodialysis unitsidentified by serial monitoring of the virus infection

To examine whether hepatitis C virus (HCV) infection still occurs in haemod ialysis units even after a decrease in the number of blood transfusions and in those contaminated with HCV, we tested anti-HCV antibodies and HCV RNA in 142 patients from Japanese haemodialysis units, and examined the serial prevalence of anti-HCV antibodies in 86 patients from 1992 to 1997. A high prevalence of HCV infection was observed: 34 (23.9%) and 38 (26.8%) of the 142 patients mere positive for serum anti-HCV antibodies and HCV RNA respec tively: These positive rates were related to the duration of haemodialysis. We found that five patients treated in the same unit seroconverted from 19 93 to 1995. Four of the five patients had been treated at the same shift an d mere affected at the same time. Phylogenetic analysis of the hypervariabl e region 1 (HVR1) sequence of HCV from serum of these patients showed that three of the four patients' sequences mere phylogenetically clustered and t hat two of the three were closely related. Thus, an occasional transmission of HCV occurred in the haemodialysis unit. The universal precautions by st aff such as carefully changing gloves may be important in inhibiting spread of HCV because no instances of infection have been seen since the instigat ion of educational measures for unit staff. (C) 2000 The Hospital Infection Society.