活禽交易市场短期休市措施对控制市场H7N9病毒污染效果的评价

摘要

目的 评估活禽交易市场短期休市措施对降低市场H7N9禽流感病毒污染及人感染H7N9发病的成效.方法 收集整理2014年2月至2017年5月,中山市活禽交易市场短期休市信息、市场环境H7 RT-PCR检测数据,及人感染H7N9发病数据.RRx=休市后第X周市场环境H7样本阳性率/休市前1周阳性率×100％.结果 共实施3轮短期休市.第一轮:2014年2月10日至23日,期间周边地市未同步休市.恢复交易后,环境阳性率持续上升,RR1 =0.40 (95％CI:0.28-0.59),RR3=0.63 (95％CI:0.32-1.24),RR4=0.83 (95％CI:0.48-1.46),2015年5月份报告2例人感染H7N9病例.第二轮:2015年2月19日至28日,全省统一部署,周边地市同步休市.恢复交易后,环境阳性率持续维持在10％以下,RR1=0.15 (95％CI:0.07-0.34),RR2 =0.21 (95％CI:0.10-0.41),RR3 =0.03(95％CI:0.00-0.18),RR4=0.10 (95％CI:0.04-0.27),该流行季未再报告病例.第三轮:2017年1月8日至21日,期间周边地市未同步休市.恢复交易后,环境阳性率持续上升,RR1 =0.25(95％CI:0.09-0.68),RR3 =0.37 (95％CI:0.14-1.00),RR4=1.07 (95％CI:0.54-2.11),2017年2月报告2例人感染H7N9病例.结论 单个城市的短期休市,即使时间长达2周,一旦恢复交易,市场环境阳性率迅速上升,人感染发病的风险再次增加;区域性多个城市同步休市,市场环境阳性率能持续维持在低水平,极大地减少人感染发病的风险.%Short-term closing live poultry markets have been frequently adopted to control H7N9 epidemic.To evaluate the effect of short-term closing live poultry markets,we analyzed the data of environment surveillance of H7 by RT-PCR,and the human H7N9 cases in Zhongshan City from Feb 2014 to May 2017.RRx =The positive rate during the x-th week after closing / the positive rate of the week before closing days * 100％.Three rounds of short-term closing live poultry markets were administered.Round one:from Feb 10 to 23,2014,the neighboring cities didn't synchronize.The H7 positive rate increased since the trade recovered,and RR1 =0.40 (95％CI:0.28-0.59),RR3 =0.63 (95％CI:0.32-1.24),RR4 =0.83 (95％CI:0.48 -1.46).Two human cases were reported in May,2014.Round two:from Feb 19 to 28,2015,the neighboring cities synchronized as the province policy.The H7 positive rate maintained a level lower than 10％ since the trade recovered,and RR1 =0.15 (95％CI:0.07-0.34),RR2=0.21 (95％CI:0.10-0.41),RR3 =0.03 (95％CI:0.00-0.18),RR4 =0.10 (95％CI:0.04-0.27).No more human cases reported in that epidemic season.Round three:from Jan 8 to 21,2017,the neighboring cities didn't synchronize with Zhongshan City.The H7 positive rate had increased since the trade recovered,and RR1 =0.25 (95 ％ CI:0.09-0.68),RR3 =0.37 (95％CI:0.14-1.00),RR4 =1.07 (95％CI:0.54-2.11).Two human cases were reported in Feb,2017.Results indicated that,if the policy of closing live poultry markets was administered in single city,the environment pollution rate would rise shortly and the risk of human infection would increase once the trade recovered.However,if it was synchronously administered in all the cities in one region,the environment pollution rate could maintain at a low level and the risk of human infection would reduce enormously.