| Purpose In recent years,avian influenza A virus,H5N1,H7N7,H7N3,H7N2,H9N2,H10N7,H7N9 and H10N8 have crossed the species barrier and caused acute respiratory infectious diseases ranging from mild to severe in humans.Most importantly,the frequent gene reassortments among the flu A viruses or the newly-emerging virus caused by the reassortment were being attracted worldwide attention.Since the spring of 2013,cases of H7N9 have happened frequently in China.In December 2013,National Health Planning Commission announce that the world’s first case of human infection with H10N8 have been confirmed in Nanchang city,Jiangxi province.Previous studies have demonstrated that live poultry markets(LPMs)play a crucial role in maintenance,amplification and dissemination of avian influenza viruse,they also provid favorable conditions for the generation of novel subtypes.They are high-risk locations for human infection with avian influenza viruses and also act as the key point to the prevention and control of avian influenza.This study aimed to explore the frequency and intensity of T cells to different influenza virus antigen response,through cellular immunological methods.At the same time,carry out the cross-sectional study,to understand the risk factor for avian influenza virus infection of live poultry workers,and the contamination status of LPMs,to provide scientific basis for further public health action.Methods(1)Epidemiological survey: LPMs and poultry related workers were randomly selected as study objects.Two self-designed questionnaires were designed to obtain information on the characteristics and management of LPMs as well as hygiene practices of poultry workers.Sewage,poultry fresh feces and smears of poultry cage samples were collected after questionnaire survey,as well as poultry workers,EDTA-Na anticoagulant 20 ml as.(2)Laboratory test: Environmental specimens will be tested by real-time RT-PCR for AIVs nucleic acid within one week after being collected,then the positive specimens will be examined by the H5 and H7 and H9,H10 subtype for the specific detection.Cellular immune responses of peripheral blood mononuclear cells(PBMCs),taken from poultry workers,were determined by enzyme-linked immune spot tests(ELISPOT)using NP and M1 protein.(3)Data analysis: The database was created by Epidata3.0,using spss13.0software for statistical analysis.Statistical analysis was performed with descriptive statistic analysis,the chi-square test and analysis of variance,with P< 0.05 as there is significant differences in statistically.Results(1)A total of 76 LPMs were investigated.Of the 76 LPMs investigated,55.26%(42/76)were cleaned every day,76.32%(58/76)were sterilized at least once per week,only two rested for one day per month,97.37%(74/76)slaughtered poultry on site and 69.74%(53/76)kept live poultry overnight in markets.(2)The median cumulative time of 365 poultry workers’ exposure to live poultry was 13 years(inter-quartile range: 5 to 20 years).Of the 365 poultry workers,58.90%reported their exposure to live poultry through slaughtering and 43.01% through sale,the proportion of people exposed to poultry more than 5 days a week was 90.96% and13.97% reported having direct contact with sick or dead poultry recently.Only14.78% wore masks and 20.00% used gloves every day.Nearly half(46.58%)washed their hands every time after slaughtering poultry and before eating(52.05%)with soap or hand sanitizer(47.67%).The minority never rubbed their eyes(25.75%),touched their mouth(25.75%),and picked their nose(28.22%)with hands in the course of their work.(3)474 environment samples were collected from LPMs.Of these,75 were positive for influenza A virus with positive rate reaching 15.82%.Of these 75 positive samples,44,16,11 and 2 were positive for H9,H5,H7 and H10,respectively.Three kinds of environmental samples were positive for AIVs and the differences in positive rates are of statistic significance.(4)365 blood samples were taken from poultry workers.Of these 241 were positive for T cell response by virus NP/M1 peptides(corresponding positive rate was 66.03%).Of these 241 positive samples,104 were positive for H9 subtype avian influenza virus.Response frequency decreases with the growth of age,and increases firstly and then decreases with the increase of occupational exposure time.Conclusions(1)The avian influenza control measures were insufficient in LPMs,with markets being heavily contaminated in Nanchang.Intensity of management of the LPMs should be enhanced to reduce the infection risk of avian influenza virus for live poultry workers and customers visiting LPMs.(2)There were some problems in Nanchang poultry workers,such as low influenza vaccination rates,high rate of exposure to poultry,long cumulative exposure time and lack of self-protective measures,and therefore,the possibility for potential infections is high.Public health staff should strengthen propaganda and education to improve poultry workers,self-protection awareness.(3)There were subjects with cross reaction of memory T cell immune response against H9 subtype avian influenza and seasonal influenza viruses.Age and occupational exposure time were influences on T cell response against H9 subtype of avian influenza virus NP/M1 peptides. |
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