活禽市场甲型流感病毒核酸检测分析

Detection of HA viral nucleic acid in live poultry markets and risk analysis

目的了解珠江三角洲活禽市场外环境甲型流感病毒核酸分布情况,分析高阳性率的影响因素。方法 2007年5月-2008年4月,在珠江三角洲7个城市选取42个活禽市场,使用统一的《活禽市场调查表》调查活禽市场一般情况;用拭子涂抹方法,采集外环境样品,采用荧光定量PCR方法检测甲型流感病毒核酸;对市场HA病毒核酸高阳性率的影响因素进行分析。结果共检测样品3 864份,检出HA病毒核酸阳性876份,阳性率为22.67%;7个城市均有阳性样品检出,阳性率7.23%~32.20%;每个月均可检出,9月份至次年2月份的阳性率高于平均阳性率;与鸭有关的外环境阳性率为37.53%（298/794）,高于其他样品阳性率;阳性率的影响因素有,市场位于市区（OR=9.37,95%CI=1.07~82.35）、活禽现场宰杀（OR=1.37,95%CI=1.08~1.73）、交易方式为零售（OR=1.37,95%CI=1.08~1.73）。结论活禽市场甲型流感核酸阳性率较高,市场位置在市区、有活禽现场宰杀、零售的交易方式可能是高阳性率的影响因素。

Objective To describe characteristics of hemagglutinin（HA） viral nucleic acid in live poultry markets in Pearl River Delta and to analyze potential risk factors of influenza A virus epidemic.Methods From May 2007 to April 2008,we conducted a survey in 42 live poultry markets in Pearl River Delta.Standard questionnaires were administered to market operators to collect information on market,types of birds and other animals in the markets,and cleaning and disinfecting practice.The market was visited every month and was sampled at least 4 wipes from cage surface,ground,and ditch-water.All samples were tested for viral nucleic acid of influenza A virusby real-time PCR.Risk factors were analysed for higher HA（influenza A virus） test rate.Results HA was identified in 876 of 3 864 samples tested with a positive rate of 22.67%.There were positive detections for all 7 cities with positive rates of 7.23%-32.20%.There were positive results in every month with higher positive rates from September to February than average positive rate.The positive rate related to duck was 37.53%,higher than other animals.The factors associated with higher positive rate than average included market location in town（odds ratio =9.37,1.07-82.35）,retail transaction（OR=1.37,1.08-1.73）,and slaughter in the market（OR=1.37,1.08-1.73）.Conclusion HA viral nucleic acid can be detected in live poultry markets.Market location in town,retail mode,slaughter in the market are risk factors for high positive rate.