| ObjectiveSince the 1970 s,the emergence of emerging infectious diseases and infectious diseases has become a severe public health problem.As the only member of Orthomyxoviridae,influenza virus has a wide range of hosts,including human beings,birds and other mammals like swine,horses.The segmental RNA genome leads to a higher probability of mutation,recombination and reassortment,which often result in antigen draft and antigen shift along with the emergence of new subtypes.In early years the researc hers focused on human influenza cases and ignored avian influenza because of the low incidence and diagnosis.The surveillance of avian influenza had been activated since the 1970 s.H5N1,H7N9 and H5N6 novel avian influenza virus began to be discovered and caused the attention of society and alarm.The outbreak of avian influenza A(H7N9)causes much more social burden and panic for the rapid spread,higher incidence and poor prognosis.In this study,we do a stage of cross-sectional study from poultry,environment,occupation exposure population.And the extended environment surveillance of avian influenza is in order to reveal the epidemiological rules and provide more scientific and reliable evidence for prevention and control against avian influenza of working for poultry related occupation.Methods4 kinds of fixed sentinels in Baiyun District were set up for the surveillance.A total of 1783 pieces of samples including environmental swabs,cloaca swabs and aerosol samples were collected in 4 stages(seasons)from October 2015 to July 2016.Real-time RT-PCR was used in the nucleic acid detection of avian influenza virus including influenza(A)universal probe and avian influenza H5/H7/H9 subtype classification probes.Besides,a total of 300 serum spec imens of poultry workers were collected in the sentinels mentioned above.A serological surveillance of avian influenza H5/H7/H9 specific antibodies was executed,using he magglutination inhibition test SPSS 17.0,GraphPad Prism 5.01 and Microsoft Excel 2010 softwares were used for statistical analysis and chart production.ResultsThe positive rates of influenza(A)universal probe among the four stages in this study were 22.72%,19.74%,29.65% and 23.40%,respectively,with a chi-square value of 12.500(p<0.01).After the classification of the positive samples,most of them were non-H5/H7/H9 subtype(34.6%~90.6%),followed by H9 subtype(6.3%~59.0%),H5 subtype(0.6%~15.6%)and H7 subtype(1.3%~4.9%).The result of hemagglutination inhibition test showed tha t few of the poultry workers carried avian influenza H5/H7/H9 specific antibodies.The positive rate of specific antibodies to avian influenza H5/H7/H9 were 1.0%(3/300),0%(0/300)and 5.67%(17/300),respectively.Conclusions 1.The intermediate circulation of poultry trading was considered to be the source of the environmental pollution of avian influenza virus,which should be highlighted and focused on.2.There were seasonal differences in the environment pollution of avian influenza virus,which infer that the avian influenza prevention and control should be targeted according to the epidemic rules.3.The level of specific antibody of avian influenza among poultry workers was low,which indicated that the incidence of latent infection was low. |
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