Epidemiology of hepatitis C virus among long-term dialysis patients: A 9-year study in an Italian region

Background: Monitoring hepatitis C virus (HCV) antibodies (anti-HCV) in long-term dialysis patients is an important issue of public health. The aim of the study is to analyze the prevalence, seroconversion rate, and impact of HCV-positive serological test results on survival. Methods: We studied 6,412 patients starting long-term dialysis therapy reported to Lazio Dialysis Registry (Italy) between 1995 and 2003. HCV serological status was assessed by using second- or third-generation assays. Patients who were seronegative at the beginning of a period who became seropositive at the end of the same period are defined as seroconverters. Results: In 1995 to 2003, the overall prevalence of anti-HCV among long-term dialysis patients decreased from 30.6% to 15.1%; we did not observe a decrease in prevalence of anti-HCV in those starting dialysis treatment. After a decrease in the first year, HCV seroconversion rates remained stable at approximately 2 cases/100 person-years. Survival at 9 years was lower for both HCV seroconverters and those already anti-HCV positive at dialysis therapy initiation compared with HCV-negative subjects (log-rank test, P<0.001). Results of a multiple Cox model showed that subjects who were or became anti-HCV positive had a hazard ratio of 1.29 (95% confidence interval, 1.15 to 1.44) compared with HCV-negative patients. Conclusion: We did not observe a significant decrease in HCV seroconversion rates in 1995 to 2003. The overall decrease in anti-HCV prevalence could be related to the lower survival probability for both HCV seroconverters and those already HCV positive at long-term dialysis therapy initiation compared with HCV-negative subjects. Our findings confirm that additional efforts should be made to minimize the risk for HCV infection before and during long-term dialysis treatment.