AIM:To determine the prevalences of TTV and HGV infectionsamong blood donors and patients with chronic liver diseasein Korea,to investigate the association of TTV and HGVinfections with blood transfusion,and to assess the correlationbetween TTV and HGV viremia and hepatic damage.METHODS:A total of 391 serum samples were examinedin this study.Samples were obtained from healthy blooddonors(n=110),hepatitis B surface antigen(HBsAg)-positivedonors(n=112),anti-hepatitis C virus(anti-HCV)-positivedonors(n=69),patients with type B chronic liver disease(n=81),and patients with type C chronic liver disease(n=19).Trv DNA was detected using the hemi-nested PCR.HGVRNA was tested using RT-PCR.A history of blood transfusionand serum levels of alanine aminotransferase(ALT)andaspartate aminotransferase(AST)were also determined.RESULTS:TTV DNA was detected in 8.2%of healthy blooddonors,16.1%of HBsAg-positive donors,20.3%of anti-HCV-positive donors,21.0%of patients with type B chronicliver disease,and 21.1%of patients with type C chronicliver disease.HGV RNA was detected in 1.8%of healthyblood donors,1.8%of HBsAg-positive donors,17.4%ofanti-HCV-positive donors,13.6%of patients with type Bchronic liver disease,and 10.5%of patients with type Cchronic liver disease.The prevalence of TTV and HGVinfections in HBV- or HCV-positive donors and patients wassignificantly higher than in healthy blood donors(P<0.05),except for the detection rate of HGV in HBsAg-positive donorswhich was the same as for healthy donors.There was ahistory of transfusion in 66.7%of TTV DNA-positive patientsand 76.9%of HGV RNA-positive patients(P<0.05).Nosignificant increase in serum ALT and AST was detected inthe TTV or HGV-positive donors and patients.CONCLUSION:TTV and HGV infections are more frequentlyfound in donors and patients infected with HBV or HCV thanin healthy blood donors.However,there is no significantassociation between TTV or HGV infections and liver injury. AIM: To determine the prevalences of TTV and HGV infectionsamong blood donors and patients with chronic liver diseasein Korea, to investigate the association of TTV and HGVinfections with blood transfusion, and to assess the correlationbetween TTV and HGV viremia and hepatic damage. METHODS: A total of 391 serum samples were examined in this study. Samples were obtained from healthy blood donors (n = 110), hepatitis B surface antigen (HBsAg) -positive onors (n = 112) = 69), patients with type B chronic liver disease (n = 81), and patients with type C chronic liver disease (n = 19) .Trv DNA was detected using the hemi-nested PCR.HGVRNA was tested using RT-PCR. A history of blood transfusion and serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were also determined .RESULTS: TTV DNA was detected in 8.2% of healthy blood donors, 16.1% of HBsAg- positive donors, 20.3% of anti-HCV- positive donors, 21.0% of patients with type B chronicliver disease, and 2 1.1% of patients with type C chronicliver disease. HCG RNA was detected in 1.8% of healthy blood donors, 1.8% of HBsAg-positive donors, 17.4% of anti-HCV-positive donors, 13.6% of patients with type B chronic liver disease, and 10.5 % of patients with type Cchronic liver disease. prevalence of TTV and HGV in fections in HBV- or HCV-positive donors and patients wassignificantly higher than in healthy blood donors (P <0.05), except for the detection rate of HGV in HBsAg-positive donorswhich was the same as for healthy donors. There was ahistory of transfusion in 66.7% of TTV DNA-positive patients and 76.9% of HGV RNA-positive patients (P <0.05) .Nosignificant increase in serum ALT and AST was detected in TTV or HGV- positive donors and patients. CONCLUSION: TTV and HGV infections are more frequentlyfound in donors and patients infected with HBV or HCV thanin healthy blood donors. There is no significant association between TTV or HGV infections and liver injury.