• blood transfusion;
  • haemodialysis patients;
  • hepatitis C virus;
  • thalassemia

summary. Hepatitis C virus (HCV) seroprevalence and risk factors in north Iran were investigated in 105 thalassemia sufferers, 93 haemodialysis patients and 5976 blood donors by second generation ELISA. Our study showed that haemodialysis patients and thalassemia sufferers were at higher risk of having HCV infection; the prevalence being 55.9% and 63.8% respectively in comparison to the prevalence of blood donors (0.5%). A confirmatory immunoblotting was employed using HCV-positive cases (54 thalassemia sufferers and 19 blood donors). The result showed that 92.6% of samples of the first group and 10.5% of the latter were positive. Thus, it can be suggested that ELISA in low-risk cases may produce considerable false positives. In HCV-positive patients with thalassemia, the incidence of HCV among different age groups and genders was similar but a strong correlation in respect to the number of blood transfusion (P=0.008) was observed. In HCV-positive haemodialysis patients, it was found that there was no correlation with liver function tests (alanine aminotransferase and aspartate aminotransferase: ALT and AST), but a significant correlation was observed in respect to the duration of dialysis(P=0.000) and the number of units transfused (P=0.000). Consequently, it still seems blood transfusion is the main factor for increasing the incidence of HCV in thalassemia sufferers and haemodialysis patients.