Isolation And Identification Of Duck Hepatitis Virus And Development Of ELISA For Detecting DHV Antigen And Antibody

Duck hepatitis virus (DHV) is the causative agent of duck viral hepatitis,an acute and fatal disease of young ducklings.Virus isolates was obtained through duck embryo allantoic sac inoculation from duckling liver samples from HuBei provinces in china. All these ducklings were diagnosed clinically dying from duck virus hepatitis.and then, development of ELISA for detecting DHV antigent and antibody.and gain some results as follow.Virus isolates was obtained through embryo allantoic sac inoculation from duckling liver samples from HuBei provinces in china. All these ducklings were diagnosed clinically dying from duck virus hepatitis.Through neutralization test,animal recurrence infectation,young duckling protection experiment and observe virus particle by electron microscope. A strain DHV-â… was obtainted and identified.Using the purified virus as coating antigen, an indirect ELISA method was developed.Optimized conditions were as following.The concentration of virus for plate coating was 3.75μg per well.P/N ration reached maximumunder the condition of serum dilution at 1:160,and the demarcation of negative and positive was most obvious at the same dilution.the threshold value of ELISA was 0.2 with OD₄₅₀.It was found use this method to monitor the antibody's level in the young ducks,this assay is sensisive and specific as well.A sandwich ELISA for detection of DHV antigen was developed by using purified duck anti-DHV IgG as the first antibody coated on the ELISA plate and rabbit anti-DHV IgG regarded as the second antibody. The results showed that the optimum working concentration of duck anti-DHV IgG and rabbit anti-DHV IgG were 2μg/ml and 3.4μg/ml, respectively. The dilution titers of positive DHV sample by ELISA was 32 times higher than that by Agar gel Immunodiffusion (AGID), and other duck hepatitis virus type-â… can also be detected by this method. No cross reaction was observed with Newcastle disease virus (NDV), infectious bronchitis virus (IBV), duck plague (DP), Muscovy duckling parvovirus(MDPV), infectious bursal disease virus (IBDV), muscovy duck reovirus(MDRV). 73 of 97 suspicious duckling liver samples showing positive detected by this method.