| Highly pathogenic avian influenza(HPAI)is an infectious disease of poultry caused by influenza virus of Orthomyxoviridae.It is an animal infectious disease with high incidence and high mortality.In recent years,the poultry industry in Changfeng County has developed rapidly,with more than 36 million poultry slaughtered annually,distributed in 14 villages and towns,and the breeding mode has various forms such as companies+farmers,scale farms,and scattered farmers.The antibody levels of H5 and H7 subtype avian influenza were detected to provide scientific basis for understanding the immune status of avian influenza,evaluating the immune prevention and control of highly pathogenic avian influenza in this county,and scientifically guiding the formulation and supplement of immunization programs.From 2019 to 2021,a total of 25130 serum samples were collected from 14 townships,547 companies+farmers,34 poultry farms and egg farms,44 commercial poultry farms and 50 meat poultry farmers at different times,varieties,seasons and regions.The H5 and H7 antibodies of HPAI were detected by hemagglutination and hemagglutination inhibition tests(HA and HI),and the antibody sites were determined according to the standard of GB/T18936-2003 diagnostic technology for highly pathogenic avian influenza.Results HI antibody titer≥2~4,individual qualified;the qualified rate of group immune antibody≥70%was judged to be group qualified.The results showed that in 25130 serum samples,there were 20104 samples with H5and H7 antibody titers greater than or equal to 2~4,and 5026 samples with antibody titers less than 2~4.The average qualified rate of antibody reached 80%(20104/25130).Among them,the qualified rates of H5 and H7 subtype antibodies in 2019 were 85%(4505/5300)and 84%(4452/5300),84.4%(4895/5800)and 82%(4756/5800)in 2020,87%(4872/5600)and 85.9%(4810/5600)in 2021;the antibody levels of avian influenza in 14 townships were uneven,and the average positive rates of H5 and H7 subtype antibodies were 76.4%(1612/2110)and 74.8%(1578/2110),respectively.The qualified rates of H5 and H7subtype antibodies were 100%(160/160),and the lowest were 40.0%(72/180)and 39%(70/180),respectively.The qualified rates of H5 and H7 subtype antibody in scale field were 79.1%(1685/2130)and 70.2%(1495/2130),respectively.The qualified rates of H5and H7 subtype antibody in scattered farmers were 62.0%(1308/2110)and 41.5%(876/2110),respectively.The qualified rate of H7 subtype antibody reached 80.1%(9948/12420)in spring and 82.5%(10486/12710)in autumn;the qualified rate of H7subtype antibody in commercial meat poultry farms was 62.4%(1329/2130),and that in egg-laying poultry farms was 87.5%(3666/4190).From the analysis of the results,the overall antibody water of avian influenza≥70%national standard level,the county’s immunization work is solid and effective,but the antibody level of free-range farmers is lower than the scale field,the antibody level in autumn is higher than that in spring,the qualified rate of H7 subtype immune antibody is uneven,and the qualified rate of antibody level is lower than H5.In summary,monitoring of avian influenza immune antibodies provides basic data support for guiding scientific immunization,preventing the prevalence of H5 and H7subtypes and the invasion of other subtypes.It is necessary to strengthen training and publicity,effectively improve the awareness of immunization prevention and control of free-range farmers,ensure that one village,one household and one needle are not missed,and ensure that the level of avian influenza antibody is at a high level throughout the year,and maximize the protection of the county.There will be no regional serious animal diseases and public health safety incidents. |
PDF Full Text Request