| PurposeLive poultry markets were suspected to play a major role in the virus perpetuation and sustaining virus circulation.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 effect of different disinfection frequency and observes the disappearance of avian influenza virus in LPMs,and provide scientific basis for further management of the poultry markets.Methods(1)Sampling:We chose 5 live poultry markets(M1-M5)with similar positive-rate of avian influenza viruses according to previous monitor results and with 2 or more traders selling live poultry.in urban areas.Different interventions were taken for all live poultry stalls in each market,and three of them were selected for subsequent sampling,and less than three stalls were all sampled.(2)Laboratory test: Environmental specimens will be tested by real-time RT-PCR for AIVs nucleic acid within one week after being collected,then positive samples were cultured and isolated by chicken embryos.(3)Data analysis: The database was created by Epidata3.0,using spss17.0 software for statistical analysis.Statistical analysis was performed with descriptive statistic analysis,the chi-square test,analysis of variance and generalized estimation equation,with P< 0.05 as there is significant differences in statistically.Results(1)1464 samples were collected from 5 LPMs.Of these,393 were positive for influenza A virus with positive rate reaching 23.88% Of these positive samples,172 were isolation positive with isolation rate reaching 43.77%.Of all kinds of sample type,waste water was the highest positive rate reaching34.42%.The positive rate of different sample types was statistically significant(X2=44.23,P = 0.000).The positive rate(X2=48.2,P =0.000)and virus isolation rate(X2=11.72,P=0.002)were statistically significant.(2)The positive rate of before and after the first cleaning was statistically significant(X2=6.6,P=0.01),and the isolation rate before and after cleaning,the positive rate of nucleic acid before and after disinfection and virus isolation rate were not statistically significant.(3)The positive rate between the different interventions was statistically significant(F = 5.05,P = 0.028).The first day of the resumption of the live poultry markets,the difference between the disinfection markets and the control market was Statistical significance(P = 0.013).(4)The difference between the five LPMs was statistically significant(Wald X2=170.897,P=0.000),and the difference of the sample time was statistically significant(Wald X2=31.743,P=0.000).Compared with the control market,the OR of M1,M2,M3 and M4 in the four intervention markets were 0.746,0.880,0.844 and 0.917 respectively.Conclusions(1)All types of specimens in the five live poultry markets were detected positive for avian influenza virus,and the avian influenza virus was isolated from all types except the pigeon.The highest positive rate was found in waste water,followed by chicken throat swabs and containers;the highest isolation rate was found in chicken throat swabs,followed by defeathering machine and waste water.(2)Before and after the first cleaning and disinfection of the four interventions,only before and after cleaning the positive rate was different.On the first day of resumption,the positive rate and the rate of virus isolation were stabled at the same level.The positive rate in the disinfection market environment samples rose to a stable level of pollution within 1 hour and was lower than the control market at the same time and the first test of the results disinfection markets.(3)Compared with the control market,the effect of interventions daily disinfection,disinfection once every 3 days and every 7 days of disinfection once were significantly obvious.The effect of daily disinfection of the most obvious in this study,the daily positive rate were lower than the control market.The positive rate rose to be the same with the first sampling within 48 hours,and the virus isolation rate was restored to the pre disinfection state within 72 hours. |
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