Monitoring Analysis Of H7N9 Avian Influenza Of Poultry In Shaanxi Province

H7N9 influenza is a new type of influenza A,in March 2013,the first human infection of H7N9 influenza virus in Shanghai,and in Shanghai to test the farmers ' market pigeon samples detected H7N9 influenza virus,followed by 2017 a total of five waves of human infection H7N9 influenza virus outbreak,affecting several provinces in the country,A cumulative total of more than 1500 people have been infected.Poultry infection H7N9 influenza virus,the basic non-performance of clinical symptoms,generally subclinical a sexual infection.At the beginning of 2017,the gene loci of H7N9 influenza virus mutated,which showed high pathogenicity to poultry.In March of the same year,a high pathogenic H7N9 influenza outbreak occurred in Dongan County,Yongzhou,Hunan province,where 170,000 poultry were culled.In the following year,poultry H7N9 influenza outbreaks occurred in several provinces,causing significant losses to the domestic poultry industry.In this study,a cross-sectional survey method was used to investigate H7N9 influenza infection in poultry farms,ancestral and parental poultry farms,live poultry trading markets and other places in Shaanxi province.The distribution and infection of H7N9 influenza in poultry in the province were preliminarily grasped,which provided scientific basis for the prevention and control of H7N9 influenza in poultry.1.Real-time quantitative RT-PCR was used to detect the pathogen of H7 subtype influenza in 41189 cotton swabs collected from 4014 surveillance sites,none positive samples were detected.2.117358 Serum samples of poultry free immunized with H7N9 influenza vaccine were tested for H7 subtype infection antibody by hemagglutination and hemagglutination inhibition(HA/HI)test,and 638 positive samples were detected at 85 farm sites,with an individual positive rate of 0.54% and a group positive rate of 2.12%.The results showed that there were H7N9 influenza seropositive birds in Shaanxi Province.Among them,Yulin poultry farm H7N9 Influenza individual positive number and field group positive number are the highest,accounting for the province's individual positive number and field group positive number of 50.59% and 71.16%,respectively,from different breeding patterns,live poultry Market group positive rate and individual positive rate are much higher than other breeding patterns.