Studies On The Epidemiological Status And Prevention Of GP In Weifang

30 virus strains were isolated from infected geese in weifang of Shandong province using goose embryos. 27 virus strain of them were identified as GPV in agar diffusion test, neutralizng test of goose′s embryos,artificial infection experiment and hemagglutination test. Situation of these sick geese flocks with GP , such as feeding area,time,goose breeds,day old ,incidence,mortality,etc, was collected and statistically analyzed. Serum of these sick geese with gosling plague were collected for detecting titers of antibody to GPV by agar diffusion test. We detected the ELD50 of the GPV strain linqu-I (GPV-L-I) to 12-day-old goose embryos was 10-6.5/0.3ml. 8-old-day unimmunized geese were inoculated with these isolates of GPV. As a result,all the tested goose showed a 100% incidence and a 50%～100% mortality respectively. The epidemiological results showed that GP broken out during 2006 in Weifang including Gaomi,Linqu,Zhucheng,Changle etc. GPV could infect different ages and species goose in 4～8 Month in Weifang Region, but it was most popular in 5～7 Month and in 1~21 days old geese. The younger the geese were, the higher mortality rates was. When 7-day-old goose were infected by GPV,the mortality rates of it was more than 90%. Of the 30 cases, the carrier rate was 50%(15/15), and the infection rate of Escherichia coli was 26.7%(8/30).The oil-emulsion inactivated vaccine against GPV, including the GPV-L-I, is reliable and safety in chicks.Its immune efficiency is excellent. Hyperimmunized egg-yolk antibodies against GPV were developed by immunizing commercial hens three times with the inactivated vaccine. The treatment test showed that the earlier the geese were injected egg-yolk antibodies, the higher cure rates was. It is concluded that the use of antibodies caused by local strain exhibits greater potential to treat the sick goose flocks with GP with possible variations.A Pair of primers were designed and synthesized based on the VP3 gene of goose plague virus . VP3 gene of goose plague virus were amplified from the DNA by Polymerase Chain Reaction (PCR), the Vp3 gene were cloned into PMD 18_T vector respectively. The recombinant plasmid were identified with restriction endonuclease analysis and PCR, and then sequenced. The result of sequence analysis showed that VP3 gene had 375bp . the strains of GPV shared highly common identity(95.4-99.9%) The causes of GP outbreaking in some areas of Weifang were analysed and a rule of biosecurity against it were made. The rule was applied in 27 farms where GP have been found before. The results indicated that the rule was applicable. The reduction rates was 77.8%.