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Investigation For The Prevalence Of Avian Influenza Viruses In The Related Environments In Mainland China, During2010-2012

Posted on:2014-10-16Degree:MasterType:Thesis
Country:ChinaCandidate:Y ZhangFull Text:PDF
GTID:2283330401976048Subject:Public Health
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Objectives:Influenza A virus can be isolated from birds and mammalian animals, such as humans, swine, horses, tigers and marine mammalian. Wild aquatic birds are the reservoir of influenza A virus, the apparent healthy ducks, geese and birds may shed and excrete viruses to the environments around them. One of risk factors for infection with H5N1cases are visiting live poultry markets. To investigate the prevalence of avian influenza viruses in the related environments, we performed a project to test the avian influenza virus distribution in live poultry markets, poultry farms, poultry packing factories in31Provinces in China from2009to2012.MethodsA total48706samples from poultry related environments were collected from live poultry markets, poultry farms, poultry packing factories from2009to2012. A total187911samples from live poultry markets,26269samples from poultry farms,3536samples from poultry packing factories.A total of12928feces,17268swabs from cages,8259drinking water of birds,5003water of sewage,2779swabs of chopping boards were collected. Samples were tested for influenza A nucleotide by real-time reverse transcription polymerase chain reaction (rRT-PCR) and rRT-PCR positive samples were isolated in embryonated eggs. Subtypes of the isolates with hemagglutination positive were determined by one-step rRT-PCR using specific HA and NA primers.Results:Avian influenza viruses can be isolated from the environments of live poultry markets, poultry farms, poultry packing factories in the whole year from2010to2012, with a seasonal peak during winter and spring season.For analysis the differences of variety of sampling places and sampling types for virus detection using both rRT-PCR and egg culture test, the samples were divided2parts according provinces from South or North of China.During2012-2012, In South Provinces environmental sample the nucleotide and isolation positive rate of influenza A for rRT-PCR were6.11%and1.13%respectively,in northern province environmental sample the nucleotide and isolation positive rate of influenza A were0.93%and0.10%respectively, environmental sample the nucleotide and isolation positive rate of influenza A separation rate was significant difference between southern province and northern provinces (P<0.01).In the southern province of live poultry market, poultry farms, poultry packing factories environment sample the virus nucleic acid positive rate type A influenza were10.02%,1.72%and5.74%respectively. Southern provinces different monitoring sites environmental samples of type A nucleic acid positive rate exists significant difference (P<0.01).The isolation positive rate of influenza of environment sample of live poultry markets, virus samples from poultry, poultry packing factories were1.89%,0.23%and0.92%respectively. Southern provinces different monitoring sites environmental samples of the isolation positive rate exists significant difference (P<0.01)。In the northern province of live poultry market, poultry farms, poultry packing factories environment sample the virus nucleic acid positive rate type A influenza were10.02%,1.72%and5.74%respectively. Southern provinces different monitoring sites environmental samples of type A nucleic acid positive rate exists significant difference (P<0.01)。The isolation positive rate of influenza of environment sample of live poultry markets, virus samples from poultry, poultry packing factories were1.89%,0.23%and0.92%respectively, northern provinces different monitoring sites environmental samples of the isolation positive rate exists significant difference (P<0.01)。During2012-2012, influenza302was isolated in the environmental samples. mainly H5N1subtype (57.94%) and H9N2subtype (26.49%).H3, H4, H6, H11subtypes and N6, N8, N9subtypes also has been isolated. Live poultry markets and poultry farms,H5Nl subtype of avian influenza virus separation rate is0.99%,0.02%and0.03%respectively, different monitoring sites subtype H5N1viruses isolated rate exists significant difference (P<0.01); H9N2subtype avian influenza virus separation rate were0.17%,0.32%and0.09%respectively. Different monitoring sites subtype H9N2virus separation rate exists significant difference (P<0.01).After statistical analysis, urban and rural live poultry markets and poultry farms in different environmental samples of type A nucleic acid positive rate exists significant difference (P<0.01). Poultry slaughter plant samples of different type A nucleic acid positive rate there was no significant difference (P>0.05)Conclusions1.Avian influenza viruses can be isolated from the environments of live poultry markets, poultry farms, poultry packing factories in the whole year from2010to2012, with a seasonal peak during winter and spring season.2. The rRT-PCR positive rate of influenza A virus nucleic acid in the southern province environment positive rate and virus separation rate is higher than the northern provinces.3. The different monitoring sites in north and south provinces the positive rate of influenza A virus nucleic acid and the virus isolation rate exist significant differences. Live poultry markets between urban and rural areas is higher than other places of surveillance.4. Environmental sample separation is mainly H5N1and H9N2subtype virus, H5N1and H9N2viruses in different monitoring sites.Virus separation rate exist significant differences, urban and rural live poultry market environment sample subtype H5N1virus separation rate is higher than other monitoring places, the poultry farm environment sample subtype H9N2virus separation rate is higher than other places of surveillance.5. The live poultry markets and poultry farms in different environmental samples of type A nucleic acid positive rate exists significant differences.
Keywords/Search Tags:avian influenza virus, environment, poultry, live poultry market, poultryfarm, poultry packing factory, feces, drinking water, cage
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