Objective To study the distribution and pathogenicity of transfusion transmitted virus(TTV) in liver diseases of unknown etiology and the infection rates of TTV in healthy person in Hei Long jiang province.Methods TTV was detected by semi nested polymerase chain reaction (PCR) in 80 patients with liver diseases of unknown etiology,11 healthy blood donors and 9 convalescent patients of TTV positive with acute liver diseases. Results TTV positive rates was 18.75%(15/80) in liver disease of unknown eti...