[Infection by hepatitis C virus in patients on hemodialysis: prevalence and risk factors].

CONTEXT: Chronic renal disease patients on hemodialysis are at increased risk of infection by hepatitis C virus (HCV). High prevalence rates have been reported from dialysis units worldwide. Recent studies have shown an inverse relation between HCV infection and life expectancy of patients on hemodialysis and those undergoing renal transplant.

OBJECTIVES: Assess the prevalence of and risk factors for HCV infection in patients undergoing hemodialysis.

METHODS: A cross-sectional study was undertaken from January to December, 2007. During this period, 236 patients were tested for anti-HCV antibodies with third generation ELISA. Those who tested positive further underwent qualitative PCR testing for HCV-RNA. A subject was considered HCV-infected if both tests (anti-HCV and HCV-RNA) were positive. Monthly serum ALT and the mean for the 12-month period were obtained from 195 patients. Two hundred eight (88.1%) patients answered a standardized questionnaire aiming to identify risk factors for HCV infection.

RESULTS: Of the 236 subjects studied, 14.8% (35/236) tested positive for anti-HCV antibodies. Of these, 71.6% (25/35) tested positive for HCV-RNA. Chronic HCV infection was thus prevalent in 10.6% (25/236). Bivariate analysis showed time on hemodialysis, number of blood transfusions, previous peritoneal dialysis and previous sexually transmitted diseases to be the main risk factors for HCV infection. Yet multivariate analysis showed that just time on hemodialysis and previous sexually transmitted diseases were significantly associated with HCV infection. Patients on hemodialysis for over 10 years were 73.9 (CI 17.5-311.8) times as likely to have acquired HCV, compared with those on hemodialysis for up to 5 years. Patients with previous sexually transmitted diseases had a 4.8 times higher risk of HCV infection compared with those without previous sexually transmitted diseases. Mean serum ALT was significantly higher in HCV-infected patients (44.0 +/-13.5 U/L versus 33.5 +/- 8.0 U/L, P<0,001).

CONCLUSION: HCV infection was highly prevalent in the dialysis unit studied. Time on dyalitic treatment and previous sexually transmitted diseases were the main risk factors for HCV infection. HCV-infected patients on hemodialysis had higher serum ALT levels than those without chronic HCV infection.