广州市活禽交易市场休市效果评估队列研究

The Cohort Study on Effect of Monthly Closing Day in Live Poultry Markets in Guangzhou City

[目的 ]了解目前广州市活禽交易市场每月休市一次(天)的实施效果,给人感染H7N9等流感病毒的科学防控提供技术依据。[方法 ]2015年3月,选择广州市某区1个活禽批发市场和2个活禽零售市场,分别于休市前、休市中,以及休市后的1、2、3、4、5、7、14、21和28天,采集市场内环境棉拭子和活禽口咽/泄殖腔棉拭子,共2 470份,进行通用型禽流感病毒荧光RT-PCR检测。[结果 ]研究发现,休市前、中、后各检测时点,环境样品中禽流感病毒阳性率分别为17.78%、10.00%、5.19%、29.63%、21.48%、22.96%、22.22%、45.93%、40.74%、47.41%和25.19%。虽然活禽交易市场在休市后禽流感病毒有非常明显的减少,但是阳性率在休市后第二天就开始显著升高,而且环境样品中病毒阳性率与活禽样品中病毒阳性率呈明显的统计学相关性(Pearson相关系数为0.82)。[结论 ]本研究是国内首次活禽交易市场(包括活禽批发市场和活禽零售市场)每月一次(天)休市效果的队列研究。研究显示,每月一次(天)的休市能迅速减少活禽交易市场内禽流感病毒的污染,但是随着市场的重新开放,感染禽流感病毒活禽的重新进入,市场内禽流感病毒阳性率再次迅速升高。推测仅仅依靠每月一次(天)的休市措施,无法从根本上降低本地区活禽交易市场内禽流感病毒的污染程度以及人感染禽流感的风险,需进一步调整防控策略,采取综合的防控措施。

[Objective]For the purpose of providing technical evidence for scientific control of human H7N9 infection, evaluating the effectiveness of monthly market closing measure. [Methods] One wholesale live poultry market and two retail live poultry markets in Guangzhou city were selected in March 2015. The environmental swabs and live poultry oral/cloacal swabs were sampled before, during and after the market closing day, and 2 470 samples were collected in total and then tested for type A avian influenza virus （AIV） by fluorescence RT-PCR. [Results] The positive rates of virus in environmental samples in 11 rounds samplings were 17.78%, 10.00%, 5.19%, 29.63%, 21.48%, 22.96%,22.22%, 45.93%, 40.74%, 47.41% and 25.19%, respectively. The results showed that although the positive rate of AIV declined dramatically on the day just after the market closing, the rates increased significantly from the second day afterwards. Besides, the positive rate of virus in the environmental samples increased with a similar trend to that of the poultry samples （Pearson correlation coefficient was 0.82） .[Conclusions] This study is the first reported cohort study on the effect of monthly closing day in live poultry markets of China. The results indicate that although the monthly market closing practiceappearsto reduce AIV loads in LPMs, the effect is temporary.And it is indicated that AIV positive rate rose sharply again with the opening of the market and re-introduction of AIV infected live poultry. This suggests that the monthly market closing measure alone maynot be sufficient to control and eradicate AIV in this area.