| Through consultation with some laying hen farmers,county experts came to investigate and found that H9N2 subtype AIV still exists in Yishui County.Although the virulence of the H9N2 subtype AIV is weak,its distribution is extremely wide,and the harm is persistent and difficult to control;although there are no characteristic symptoms,it can cause a decline in egg production and vaccine immunization failure.The prevalence of the disease in Yishui County is not clear.Yishui County’s chicken stock reached 3.433 million at the end of the year in 2019,with a slaughter of 16.412 million that year;duck stock of 5.828 million at the end of the year,with a stock of 16.414 million that year;goose stock of 56,000 at the end of the year,with a stock of 21,000 that year.If H9N2 subtype AIV is widespread in Yishui County,it will bring serious harm to the poultry industry in Yishui County.In order to study the epidemic situation of avian influenza H9N2 subtype in Yishui County and the prevention and control of H9N2 subtype avian influenza in farm households and animal epidemic prevention departments,an epidemiological investigation on avian influenza H9N2 subtype in Yishui County was conducted in 2019,and RT-PCR detection was carried out,and sampled the antibody levels of laying hens to further clarify the prevalence and immunization of avian influenza H9N2 subtype in Yishui County,and through the evaluation of the H9N2 avian influenza prevention and control situation of farm households and animal disease prevention and control institutions in Yishui County Questionnaire surveys and on-site interviews revealed the epidemic dynamics and epidemic risks of the virus in Yishui County,and gave different epidemic prevention priorities to different regions and different poultry breeds in Yishui County,and proposed epidemic prevention and control for farm households and animals Recommendations for the prevention and control of H9N2 subtype avian influenza.In this study,8290 poultry throat/cloacal swab samples were collected from 12 townships in Yishui County in March and September 2019 for RT-PCR detection.The results showed that the total positive rate of avian influenza H9N2 subtype virus was 3.88%（322/8290）.The positive rate of individuals in March（4.25%）was significantly higher than that in September（3.36%）.The individual positive rate of duck was the highest,3.79%（255/6730）,followed by chicken was 4.86%（53/1091）,and the individual positive rate of goose was the lowest,2.99%（14/469）.The positive rate of individuals in scale farms（3.36%）was lower than that of professional households and free-range farmers（4.63%）.Yicheng Town had the lowest positive rate of H9N2 AIV,and Cuijiayu Town and Shagou Town had a high positive rate of H9N2 AIV.The positive rate of immunized H9N2 subtype avian influenza virus was significantly lower than that of unvaccinated poultry farms.In September 2019,228 serum samples from 21 laying hens in Yishui County that had been immunized with avian influenza H9N2 subtype were tested for antibody titers by hemagglutination and hemagglutination inhibition tests.The results showed that the average titer of antibodies was 8.63 log2,the antibody pass rate（HI ≥ 6 log2）was 93.97%（1154/1228）,the virus antibody level was higher,and the immune effect was better.Among the employees of the farm households investigated in this study,the age structure is relatively large,with 36.59%（101/276）aged 36～45,and 52.90%（146/276）aged 46 and above 59.06%（163/276）of junior high school graduates and above,19.93%（55/276）of college graduates and above;31.16%（86/276）of those with a long working time,working for5 to 10 years,33.33%（92/276）of those with more than 10 years;71.05% of those who joined cooperatives.About 32% of the various indicators of the facility configuration of the farm are relatively formal.The number of employees in the farms is less standardized,and some free-range farmers do not pay much attention to the avian influenza H9N2 subtype virus.There are 176 veterinarians and related professional and technical personnel in Yishui county and township animal epidemic prevention departments surveyed in this study,accounting for 93.63%（176/190）of the total number of career personnel,of which 30.53%（58/190）have intermediate professional titles,with junior titles and below accounting for54.21%（103/190）;professional technicians aged 40～50 accounted for 38.07%（67/176）,and professional technicians over 50 accounted for 30.68%（54/176）.In terms of the results,the age structure of professional and technical personnel in animal epidemic prevention departments is relatively large,and the number of professionals in township animal husbandry and veterinary departments does not match the breeding volume in the jurisdiction.In addition,there is not enough attention to low pathogenic avian influenza such as avian influenza H9N2 subtype.Animal epidemic prevention departments should further pay more attention to the avian influenza H9N2 subtype,take the initiative to attack,strengthen immunization,and strengthen guidance.In this study,the prevention and control measures of avian influenza H9N2 subtype in Yishui County were studied.The research showed that farmers should take the initiative to improve their awareness of prevention and control.In the cold season,they should further strengthen the breeding management.They should pay attention to temperature,and try to keep the temperature difference between day and night within 3°C～4°C,it is especially necessary to avoid relatively large temperature fluctuations in a short period of time.In addition,it is necessary to pay attention to the humidity,maintain ventilation and ventilation,and also need to improve immunity awareness and plan immunization scientifically and rationally.Animal disease prevention and control departments should further strengthen the emphasis on avian influenza H9N2 subtypes,take the initiative to attack,strengthen immunization,and strengthen guidance.On the one hand,strengthen the epidemic prevention management of farm households,formulate biosafety management measures,further strengthen epidemic disease monitoring,strengthen quarantine supervision,and strengthen emergency management,try to provide household-by-house guidance,and purchase vaccines uniformly when necessary to help poultry farm households improve.Prevention and control efficiency of H9N2 subtype avian influenza.On the other hand,cultivate and attract talents through various trainings,focusing on cultivating young breeding talents who understand agriculture and love the countryside.To sum up,this study revealed the epidemic dynamics and epidemic risk of the virus in Yishui County through the epidemiological investigation of avian influenza H9N2 subtype in Yishui County and its prevention and control measures,and put forward more targeted suggestions.A plan for the prevention and control of H9N2 subtype avian influenza has been proposed for farm households and animal disease prevention and control departments.This study will also provide reference for the prevention and control of H9N2 subtype avian influenza in other county areas similar to Yishui County,and provide technical support for the prevention and control of local H9N2 subtype avian influenza. |
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