Isolation, Identification And Studies On Pathogenicity Of WF1001Strain Duck Hepatitis Virus Type1

Duck virus hepatitis（Duck viral hepatitis）is composed of duck hepatitis virus（Duckhepatitis A virus, DHAV）, a highly contagious and fatal disease in young ducklings（Woolcock,2003）. The disease mainly infects duckings which age of1-3weeks. With thedevelopment of waterfowl industry in China, the morbidity and mortality rates of DHAV arerising.The disease has become one of the major diseases for healthy development of duck. ADHAV-1isolate from Weifang City of Shandong Province was used to experimentally infectSPF ducklings.Pathological autopsy, tissue section hematoxylin （H） and eosin （E）stainingwere adopted to systematically research and illustrate the pathogenesis of the DHAV-1isolate to ducklings. This research mainly includes the following contents:1. Isolation and identification of1strains of type1duck hepatitis virusThe virulence through the median lethal rate of duck embryo and ducklings, by animalinoculation, indirect immune fluorescence, fluorescent quantitative RT-PCR method to studythe virus in different parts of ducklings load.Duck embryo lethal dose was10-5.7/0.2mL.2. Study the pathogenicity of DHAV-1This research mainly determines the virulence through the median lethal rate of duckembryo and ducklings, by animal inoculation, indirect immune fluorescence, fluorescentquantitative RT-PCR method to study the virus in different parts of ducklings load.Thisresearch can provide theoretical basis for a deeper understanding of the pathogenicmechanism of DHAV-1. According to the real-time fluorescent quantitative RT-PCR methodfor detection of DHAV-1virus which has established by our laboratory to detect the viruscontent of ducklings, analysis with different doses were quantitative dynamic on the amountof virus load of DHAV-1after the infection of1h,2h,6h,12h,18h,24h,36h,48h,72h and96h in ducklings body in various tissues. The amount of virus in the liver is highest, and thevirus content and toxic dose have relations.The virus can be detected in heart, liver, spleen, kidney, thymus, bursa.Also virus content and the time of i nfection have relationship.