Incidence and risk factors of hepatitis C virus infection in a haemodialysis unit.

BACKGROUND Hepatitis viruses have become one of the main infectious problems in patients on maintenance haemodialysis. The aim of this study was to prospectively investigate the incidence of de novo hepatitis C virus (HCV) infection in a haemodialysis unit and to identify factors currently involved in HCV transmission to haemodialysis patients. METHODS One hundred and fourteen anti-HCV negative and HCV-RNA negative patients who started long-term haemodialysis were followed for a mean period of 36 months (range 18-56). Liver tests and anti-HCV were performed at 6-month intervals. Factors that might be implicated in HCV transmission, such as blood transfusions, sexual habits, surgery and other invasive procedures, were recorded. HCV markers were re-examined in transfused blood and the HCV genotype was investigated in seroconverters to anti-HCV and in patients with previous HCV infection who were treated in the vicinity of those who seroconverted. RESULTS Eight patients (7%) seroconverted to anti-HCV and seven of them became HCV-RNA positive. HCV markers, including HCV-RNA, were negative in the blood transfused to seroconverters. No differences between seroconverters and non-seroconverters. No differences found in other risk factors not directly related to haemodialysis. The investigation of HCV genotype suggested that HCV transmission was not restricted to patients treated in the vicinity of previously HCV infected patients. Occasional failure to observe strict measures of asepsis was detected in the haemodialysis unit and this was the only factor that might be incriminating. CONCLUSIONS HCV acquisition in patients on haemodialysis is currently not related to blood transfusion, and nosocomial transmission within the haemodialysis unit seems to be the main mechanism of HCV infection. Extremely careful observation of preventive measures seems essential to eradicate HCV transmission in haemodialysis units.