INCIDENCE OF AND RISK-FACTORS FOR HEPATITIS-B VIRUS AND HEPATITIS-C VIRUS-INFECTION AMONG HEMODIALYSIS AND CAPD PATIENTS - EVIDENCE FOR ENVIRONMENTAL TRANSMISSION

Hepatitis B virus (HBV) serum markers (HBsAg, anti-HBs, anti-HBc) and antihepatitis C antibody (anti-HCV) were prospectively followed in hae modialysis and CAPD patients. From January 1987 to January 1990, 185 p atients on haemodialysis and 124 on CAPD were analysed. Among patients susceptible to HBV (69 on haemodialysis and 70 on CAPD), there were 1 7 HBsAg seroconversions on haemodialysis (0.19/patient-year) and 1 on CAPD (0.01/patient-year). A Cox proportional hazards model showed that haemodialysis treatment was the only risk factor significantly associ ated with HBV infection, thus suggesting transmission through the envi ronment. Regarding hepatitis C, 83 anti-HCV-negative patients on haemo dialysis and 46 on CAPD were followed. There were 18 seroconversions o n haemodialysis (0.15/patient-year) and two seroconversions on CAPD (0 .03/patient-year). Haemodialysis treatment was also the only risk fact or significantly associated with a higher risk of HCV infection. The h azard ratio for HCV infection in haemodialysis patients was 5.7 compar ed to CAPD patients. Nevertheless, for one patient on CAPD treatment t ransfusions were the only possible source of HCV infection. In conclus ion, both viruses were transmitted mainly through the haemodialysis en vironment, but the role of transfusions could not be excluded.