| The spread of avian influenza A virus(AIV or FluA)has serious threat to human health and cause huge economic losses.Poultry plays an important role in the diet culture,and people living in Guangdong province,Guangzhou,has its unique way of eating chicken,that people go to poultry markets to choice tasty chicken.In recent years,infected FluA patients with a history of exposure to poultry markets were increasing,this indicates directly contacting with the dressed poultry exists the risk of infection with avian influenza virus.In view of this,the study has carried on the research of FluA pollution condition of dressed poultry in different markets,Guangzhou city,FluA pollution condition of dressed poultry in three different samples and analysis of pollution source about FluA in dressed poultry,to the ministry of agriculture food safety and other relevant health authorities provide a scientific basis for FluA prevention and control policy.All get the following results:(1)Building analysis index system of FluA in dressed poultry in Guangzhou cityEstablishing FluA detection rate,avian influenza virus infection rate and different and index system of subtypes of H5 and H7 and H9 in dressed poultry.Real-time fluorescent quantitative RT-PCR to determine the RNA of FluA and determine different subtypes;By measuring half tissue culture infection dose(TCID50)to determine the avian influenza virus infection.Results show that it was established amplification efficiency of fluorescence quantitative RT-PCR is 90.9%,the standard curve correlation R~2=0.998,effectively identifying the H5 and H7 and H9 subtypes.Significantly the MDCK cells infected with avian influenza virus have disease phenomenon and virus titers show obvious gradient relationship,it can be used for the determination of infection.(2)Analysis of the pollution of FluA in different types markets in Guangzhou cityFor 4 types of 8 representative markets tracking sampling for six months,about live poultry wholesale,retail,street retail,supermarkets,total sampling 1377,the wholesale market in 359,supermarket in 147,retail market in 871,their FluA detection rate of 47.4%,5.4%and 67.5%respectively,the infection rate was 29.2%,0.0%and 44.1%,different types of market FluA detection rate and the infection rate differences have statistically significant(P<0.05).Retail market of avian influenza virus detection rate and the infection rate higher than the wholesale markets and supermarkets,supermarket detection rate of the lowest.Also,analysis of the same tissue samples in different markets,according to the wholesale market and supermarket of avian influenza virus detection rate,infection rate,and the amount of live virus RNA content is lower than the retail market.Analysis of different markets of H5 and H7 and H9 subtypes distribution in different markets,various markets all have H7 and H9 mixed distribution,and mainly for H9 subtype,a small amount of H7 subtypes,live poultry retail market has only a few H5 distribution.Wholesale market in the lungs of RNA content of low copy number of samples than other types of market is more,in the retail market contains RNA more high copy instead of H5 and H7 and H9subtype.Based on RNA content in different markets and the determination of FluA infectious,analysis of different market characteristic of avian influenza virus infection in dressed poultry,the results show that retail market(Changban R=0.372,P<0.001;Fushan R=0.560,P<0.001)relative to wholesale market(R=0.259,P=0.209)and supermarkets have high infection.(3)Analysis of the pollution of FluA in different tissue of dressed poultry in Guangzhou cityCollecting the different tissue of dressed poultry about oropharyngeal,cloacal and visceral cavity swabs during 6 months,total oropharyngeal samples collected 460,cloacal swabs 447 and visceral cavity swabs 470,the three type samples detection rate of 60.0%,52.0%and 53.8%respectively,statistically significant difference(P<0.05);Three infection rates were 43.9%,38.9%and 43.9%respectively,the difference is statistically significant(P<0.05).Median with interquartile distribution statistical analysis showed that the oropharyngeal samples of avian influenza virus RNA content in the upper quartile distribution concentration reached 10~6 copies/mL,other samples of RNA content is relatively low,live virus content in different tissue parts are near the detection limit qualification,oropharyngeal samples live virus concentration is greater than the amount in the upper quartile distribution in cloacal and visceral cavity swabs.Analysis of the same market chicken in different tissue of the dressed poultry,the same show oropharyngeal samples of avian influenza virus detection rate,infection rate,RNA content and live virus content is the highest in the three samples.Different samples of H5 and H7 and H9 subtype about avian influenza virus,suggesting that different samples are H9 subtype.Analysis correlation of different samples of infected live virus and RNA copy number found that infectious avian influenza virus in oropharyngeal sample is stronger,followed by the visceral cavity samples.(4)Analysis of pollution source about FluA in dressed poultry in guangzhouSelected a retail and wholesale market,synchronization of live poultry and environmental samples,analysis of the avian influenza virus pollution source in dressed poultry in Guangzhou.About 6 kinds of samples(live poultry oropharyngeal and cloacal,dressed poultry oropharyngeal and cloacal,visceral cavity and environment)from the two markets,show live poultry oropharyngeal samples in retail market of virus detection rate(79.6%)is highest,after environmental samples(77.2%)and live poultry cloacal swabs samples lowest(18.8),sample differences statistically significant(P<0.05),at the same time,the wholesale market has the same result.The degree of pollution about dressed poultry directly was affected by avian influenza virus in live poultry and environment.In addition,from the two markets retail and wholesale respectively selecting 40 live poultry do one-on-one experiment from the live poultry to dressed poultry,analysis of corresponding samples about live poultry and close contact with the environment conditions samples.The results show that the sample in the oropharyngeal sample pollution comes mainly from live poultry,cloacal swabs of sample pollution comes mainly from the environment and other slaughter link pollution;Live poultry in wholesale market relatively was weak level of live poultry and environmental pollution than retail market.Before live poultry slaughter in wholesale market,the original environment of the FluA virus content is lower than the retail market,but in the process of slaughter,based on the booth original environment produced the new environment with higher avian influenza viruses,the new environment of the FluA virus content is closely related to the initial amount of live poultry pollution.This study shows that the live poultry retail market about FluA virus is the most polluted,FluA virus mainly comes from live poultry and environment.Little avian influenza virus in supermarket,almost no pollution of live virus,no risk of avian influenza virus virus infection. |
