The Latent Infection Investigation Of H₅N₁ Subtype Avian Influenza Virus In Yanzhu Region In Autumn And Summer

Objective To research the prevalence of H5N1 subtype avian influenza in Yanzhu region. Investigate the relationship between avian influenza and poultry (chicken, duck).Direct the prevention and control of avian influenza.Methods Investigate and analysis the relevant factors of avian flu in influencing and occurrence.We made yanzhu village liangshui Ziyuan regional which occurred H5N1 subtype avian influenza in 2005 and around 3km is infected areas, Tangdong village which is 10 km outside and never avian influenza epidemic is no-infected area. in Nov 2008,we blooded 82 chickens and 30 ducks in infected area,42 chickens and 22 ducks were blooded in no-infected area. in July 2009,we blooded 89 chickens and 47 ducks in infected area,60 chickens and 28 ducks were blooded in no-infected areas. Separated the serum, Experimentd by enzyme-linked immune sorbent assay, according to the test results,investigate the source of infection and transmissionResults1.400 serum samples,176 were positive,with a total infection rate 44%. 2. The positive rates in infected areas and non-infected area:248 serums were detected in infected area, the infection rate is 49.12%; 152 serums in non-infected area,42.11% infection rate. The infection rate of latent epidemic in epidemic area and non-epdemic area have no significant difference (P> 0.05).3. The comparison of infected rate in infected and non-infected areas at different time:In Nov 2008, the latent positive rate of H5N1 subtype virus in infected region is 64.29%, in non-infected area is 62.50%;in July 2009,the latent positive rate is 29.41% in infected region,27.27% in non-infected area;the latent positive rate in November 2008 (63.6%) was higher than July 2009 (29%)(P<0.05)4. The infection rate of Chickens and ducks:in Yanzhu region the total positive rate of chickens is 59.34%, the positive rate of ducks is 11.02%, the latent infected rate is significant different between chickens and ducks (P<0.05).Conclusion1. chickens and ducks which are clinical health are generally susceptible on the H5N1 virus, there have the spread of avian influenza virus in Yanzhu region2. Both Chicken and duck can act as the main source of avian influenza, in which the chicken more likely to be the source of infection.3.The infection rate is higher in autumn, strengthen prevention and control of bird flu,especially in the autumn.