Risk factors for dialysis-associated hepatitis C in Venezuela.

Utilizing the first and second generation of enzyme immunoassays which detect antibodies to the C virus we investigated the frequency of anti-HCV antibodies in 315 patients undergoing hemodialysis. Other subpopulations at risk were used as reference groups. One hundred and twenty-three samples (39%) from the hemodialysis group repeatedly showed anti-HCV positive antibodies while only 19% and 1% were positive in the reference groups. The rate of anti-HCV reactive patients correlated with time on hemodialysis (less than 1 year, 17%; 1 to 5 years 43%; greater than 5 years, 64%; r = 0.94, P less than 0.001) and with the number of blood transfusions (1 to 10, 40%; greater than 10, 76%; r = 0.97; P less than 0.001). Length of time on hemodialysis was shown to be the major risk factor in thirty-three anti-HCV positive patients who had no previous record of blood transfusions. Co-infection with HBV was demonstrated in 41% out of 123 anti-HCV reactive patients, and increased alanine aminotransferase (ALT) activity was documented in this co-infected group. Our results further extend the observations on the predisposing factors to HCV spread in hemodialysis units, and suggest that in these renal patients co-infection with C and B viruses is a major cause of rising ALT activity.