鸭乙型肝炎病毒感染的研究

Experimental duck hepatitis B virus infection

Cherry valley ducks were infected by intravenous injection of DHBV positive serum in order to study the intrahepatic distribution of DHBsAg and the relation of the degree of hepatic lesions to viremia and humoral immunologic deficiency after surgical removal of Bursa of Fabricius. The anti-DHBsAg serum prepared in our laboratory showed high specificity. There was no cross reaction with HBsAg and DHBsAg was found to be located in the cytoplasm of hepatocytes as well as bile duct epithelial cells which usually showed stronger staining quality. The histopathology of liver revealed normal/mild hepatitis in the control group, moderate/severe hepatitis in the infected group. In comparison, hepatitis in the infected group was more severe in the older ducks than the ducklings, in those viremia-positive ones than in the negative ones, and in the bursectomized than in the non-bursectomized ducks. Evidently, the hepatic lesions were mostly due to DHBV infection in this series, although some other environmental factors could not be ruled out entirely. The present investigation shows that Cherry valley ducks are one of the best spices for experimental DHBV infection, and bursectomized ducks with humoral immunodeficiency might provide a reliable and useful model for the study of pathogenesis of hepatitis B virus infection.