| BackgroundAt present, the avian influenza virus has been found in poultry in most areas of China. Wild avian influenza virus cases mainly break out along the way of migratory routes and breeding grounds.Migratory birds, live poultry farms and live poultry trade are the leading causes and media for the spread of avian influenza virusesAs the largest freshwater lake in China, Poyang Lake region is an important wetland for migratory bird transnational migration perching and wintering.Poultry production conditions are favorable and live poultry breeding industry is relatively developed at Poyang Lake region.Meanwhile, there are many large live poultry and egg products markets. Live poultry trade is very frequent in this region.Human infection by avian influenza virus were reported more frequently in Poyang Lake Region, Jiangxi Province.In the last few years, human cases of bird flu like H5N1, H7N9, H10N8 have been occasionally reported.Contact with poultry or poultry products is still principal source of human infection.Objective1. To get a general survey of migratory bird protection stations, live poultry farms, live poultry wholesale and retail live poultry in Poyang Lake region 2014-2015.2. To analyze the distribution of avian influenza viruses of migratory bird protection stations, live poultry farms, live poultry wholesale and retail live poultry.3. To make a thorough inquiry of avian influenza virus distribution and the important factors of avian influenza virus which change the positive rate.By means of this study, we can learn that the Poyang Lake region migratory bird protection stations, live poultry farms, live poultry wholesale and retail live poultry involved in the distribution of avian influenza viruses. By studying the influencing factors, explore breeding and trading of live poultry in Nanchang based on the characteristics of the mode of transmission of avian influenza. This study may provide a theoretical basis for the prevention and control of bird flu warning.Method1. Questionnaire and Sample collectionIn this study, random sampling method has been used to select research sites in counties of Poyang Lake Region. The villages close to the lake were selected as sampling points. Poultry faeces, poultry drinking water, poultry feathers, swabs of cages and eggs and other specimens from September 2014 to March 2015 were collected respectively. And the samples of avian influenza were detected after egg inoculation.Environmental samples were collected and the questionnaires were filled out at the same time. Trained professional investigators interview and fill out the questionnaires.2. Laboratory testingEnvironmental samples in the study were vaccinated to chicken embryos, and then detect the virus. Positive results were screened by using the rapid diagnostic strip influenza A.3. Influence factors analysisUsing statistical methods, such as chi-square test and Logistic regression model, analysis.We have analyzed the factors which influence the bird flu virus positive rate in migratory bird protection stations, live poultry farms, live poultry wholesale and retail live poultry, such as: different sampling time, the level of the density of live poultry, the frequency of poultry house cleaning and disinfection, and whether vaccination the immunization program is complete or not.Result1. Avian influenza virus positive rate in Poyang Lake region outside environment in September 2014 is 9.04%, higher than March 2015 (3.96%).2. The external environment test results showed that, the positive rate in live poultry retail market (36.86%) is the highest in the four type places while the virus positive rate in migratory bird protection stations (0.36%) is the lowest.3. In five kinds of different specimens, the bird flu virus positive rate in a basket on the surface of the highest positive rate,9.43%(115/1219); Feather specimen were the lowest,3.33%(5/150).4. According to the test results of external environment in September 2014, the avian flu virus positive rate positive in Yugan (13.4%) was the highest. (Nanchang 11.8%, Wannian 8.6%, Xinjian 5.2%, Yongxiu6.2%) According to the test results of external environment in March 2015, the avian flu virus positive rate positive in Yongxiu (8.8%) was the highest. (Yugan 6.4%, Lushan 2.8%, Xinjian 1.8%, Wannian 0) In January 2015, the positive rates in migratory birds reserve in three counties were no statistical differences.5. Live poultry density increases result in higher positive rate.6. On farms, live poultry wholesale, live poultry retail, the positive rate of multiple factors regression analysis shows that frequency and density of live poultry disinfection are important influencing factors.7.The positive rate was 0.45%(13/2889) in farms which had complete immunization program, and positive rate was 1.92%(25/1276) in no complete immunization program farms, the external environment samples was statistically difference between the positive rate (x-=21.6, P= 0.000).Conclusions1. The risk of bird flu outbreak in autumn and winter in Poyang lake region is higher than that in spring.2. Migratory birds reserve, live poultry breeding, live poultry wholesale, live poultry retail make the bird flu virus positive rate rise rapidly.3. Live poultry density and frequency of disinfection are important factors which impact positive rate in live poultry farms and live poultry market.4. Specifications complete immunization program can effectively reduce the positive rate of farms. |
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