| Avian Influenza is a prevalent influenza that is caused by avian influenza virus. AIV not only can cause poultry infection, but also can break through the species barrier to cause mammal infection, such as mice, guinea pig, ferret, rhesus monkey, dog, cat, etc. Since case of human infection AIV was reported for the first time in 1997, there have been events of human infection AIV are reported continually, such as H1N1, H5N1, H7N2, H9N2 subtype AIV and novel H7N9 subtype AIV infect people events which form a threat to public health and human health. And AIV becomes a kind of new Zoonosis. H9N2 subtype AIV prevails throughout the world, it not only bring huge economic losses to breeding industry, but also can cause human infection and death. H7N9 subtype AIV had been found in Shanghai, anhui and other places in China, since February 2013. A total of 571 cases, 212 people were killed by February 2015. At this moment, although has not been found the evidence that infects from people to the people, but the population of AIV gives people a warning that we should especially pay more attention to Zoonosis and control the outbreak of AI from the source.This study detects H7N9 and H9 subtype AIV aerosol that uses real-time RT-PCR method in live poultry market and farms. Two pairs specific primers and probes of hemagglutinin(HA)gene and neuraminidase(NA) gene were designed and selected according to the HA gene sequences of H7 subtype and the NA gene of N9 subtype AIV available the Eurasian lineage in Gen Bank, respectively. The reaction conditions were optimized, the real-time RT-PCR assay of H7N9 subtype AIV was established. Setting up the standard curve of H9 subtype AIV according to H9 subtype AIV real-time RT-PCR method was established by our lab Lv Jing(2011). Detecting H7N9 and H9 subtype AIV aerosol samples use atmospheric particulate sampler and AGI-30 sampler.The results showed that the detection limit of H7 gene was 100copies/?L and N9 gene was 101copies/?L, H7N9 subtype AIV displayed the R2 index were 0.999 of being established H7N9 subtybe AIV real-time RT-PCR method in this experiment. The intra- and inter- assay coefficients of variation were all less than 3%. repeatability is good. The method can be used to detect H7N9 subtype AIV in the air. Established the standard curve of H9 subtype AIV, theR2 index was 0.999, which can realize the detection to H9 subtype AIV.Using of atmospheric particulate sampler and AGI-30 sampler to supervise 11-month air samples in live poultry market. Among, the atmospheric particulate matter sampler is aimed at fine particulate matter that atmospheric particulate matter is 2.5?m or less in the aerodynamic diameter, collects 33 samples. AGI-30 is to capture the particulate of different size, collects 99 samples. Using this study established detection method of H7N9 subtype AIV real-time RT-PCR detection finds that has 3/33 positive samples in air samples of being collected with atmospheric particulates sampler, July 2014, February and March 2015, respectively.Concentration is 1.06 copies/?L, 1.06 copies/?L, 1.46 copies/?L, respectively. According to the formula to calculate the virus concentration in the air, the concentration of H7 subtype AIV are 1.23×10-1copies/m3 air, 1.23×10-1copies/m3 air, 1.69×10-1copies/m3 air, respectively.Above results are detected by H7 subtype kit, the results are positive. The positive H7 samples are detected with N9, the results are positive. The concentration is 13.49 copies/?L,11.06 copies/?L, 11.54 copies/?L, respectively. According to the formula to calculate the virus concentration in the air, the concentration of N9 subtype AIV concentration is 1.56copies/m3 air, 1.28 copies/m3 air, 1.34 copies/m3 air, respectively. Other month samples and AGI-30 collected samples were not detected H7N9 subtype AIV positive.Detecting for H9 subtype AIV of live poultry market finds that each PM2.5 air sample is collected by atmospheric particulates sampler which can be detected the H9 subtype AIV positive. And concentration is 1.45×102copies/?L~7.43×104copies/?L. According to the formula to calculate the virus concentration in the air, the concentration of airborne H9 subtype AIV of live poultry market in the air PM2.5 samples is 1.68×101~8.60×103copies/m3 air. Detecting samples of H9 subtype AIV finds that each month air samples is collected positive by AGI-30 sampler. And the concentration is 1.41×102copies/?L~9.06×102copies/?L. According to the formula to calculate the virus concentration in the air, the concentration of airborne H9 subtype AIV of live poultry market in the air samples is1.07×104~6.89×104copies/m3 air. Though the particle size is different of being collect by two samplers, the tendency of the monitoring period is consistent, respectively in July, December and February showed a trend of peak.The air of live poultry market exists H9 subtype AIV particles for a long time.Collecting air and feces samples of A ~ E five chicken farms in daiyue area of Tai'an City. Detecting the air samples with H7N9 subtype AIV, the result is negative. There is no H7N9 subtype of AIV infection. Detecting H9 subtype AIV to air samples find in A and D chicken farms air samples are negative, B, C and E chicken farms find H9 subtype AIV positive results that concentration is 1.50×102copies/?L, 1.70×102copies/?L, 1.84×102copies/?L, respectively. According to the formula to calculate the virus concentration in the air, the concentration of airborne H9 subtype AIV of air of chicken farms is 1.14×104copies/m3 air, 1.29×104copies/m3 air, 1.4×104copies/m3 air, respectively. Detecting feces samples of each farm with H9 subtype AIV, results are positive and positive rate is6.25%~13.8%. Above data shows that H9 subtype AIV exists the air and feces of chicken farms, while the concentration is not high, but still has the risk of infecting people. |
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