浙江省冬春季涉禽场所禽流感病毒污染特征及影响因素研究

Avian influenza virus in various environments and risk factors for the contamination of live poultry markets during winter and spring season in Zhejiang province

目的分析浙江省涉禽场所外环境A型禽流感病毒污染特征及活禽市场被H7亚型污染的影响因素。方法2014年10月至2015年3月，于浙江省11个市的涉禽场所进行标本采集，开展禽流感病毒污染状况监测。采集的标本类型包括涉禽场所的粪便标本、笼具表面擦拭标本、禽类饮水、清洗禽类的污水、宰杀或摆放禽肉案板表面擦拭标本及其他标本。本研究共采集标本6457份，其中城乡活禽市场采集4487份，家禽规模养殖场（户）820份、家禽散养户715份、家禽屠宰加工厂118份、野生禽鸟栖息地118份及其他场所86份。采用x2检验比较不同类型或特征活禽市场、不同类型标本各亚型的核酸阳性率差异。采用多因素非条件二分类logistic回归模型分析活禽市场被H7亚型病毒污染的相关因素。结果6457份标本中，A型病毒核酸阳性率为32．54％（2101份），其中H5亚型核酸阳性率为3．67％（237份），H7亚型为12．02％（776份），H9亚型为11．77％（760份）。237个活禽市场中，H7亚型核酸阳性的占33．8％（80个）。家禽屠宰加工厂A型流感病毒核酸阳性率较高，为43．72％（101／231）（X2=737．80，P〈0．001），城乡活禽市场115／H7／H9亚型核酸阳性率较高，为27．55％（1236／4487）（x2=436．37，P〈0．001）。与售卖1种活禽的活禽市场相比，售卖1〉2种活禽的市场被H7亚型感染的0R（95％CI）值为4．58（1．63～12．87）。结论活禽市场和家禽屠宰加工厂等场所的A型禽流感病毒污染严重，售卖活禽种类较多可能是活禽市场被H7亚型污染的相关因素。

Objective To evaluate the prevalence of avian influenza virus in various environment and the influence factors for subtype H7 prevalence in live poultry markets. Methods We collected environmental samples from various environments across 11 cities of Zhejiang province between October 2014 and March 2015. Cage surface swabs, chopping board surface swabs, feces, water for cleaning, drinking water and swabs of other surfaces were collected. A total of 6 457 samples were collected, including 4 487 samples from poultry markets, 820 samples from poultry farms, 715 samples from backyard poultry pens, 118 samples from poultry processing factories, 118 samples from wild bird habitats and 86 samples from other sites. The chi-squared test was used to compare virus prevalence among sample types, sites types, and poultry markets types. Binary logistic regression was used to analyze factors on H7 subtype prevalence in poultry markets. Results Of 6 457 samples, 32.54% （2 101） samples were positive for avian influenza, with 3.67% （237） positive for H5 subtype, 12.02%（776） positive for H7 subtype, 11.77%（760） positive for H9 subtype. Of 237 live poultry markets, 33.8% （80） were positive for H7 subtype. The prevalence of influenza A in poultry processing factories was the highest at 43.72% （101/231）（x2=737.80, P〈0.001）. Poultry markets were contaminated most seriously by subtype H5/H7/H9 with the prevalence of 27.55% （1 236/4 487） （X2=436.37, P〈0.001）. Compared with markets with 1 type of pouhry, OR was 4.58 （95%C1： 1.63-12.87） for markets with 1〉2 types of poultry. Conclusion Live poultry markets and poultry processing factories were contaminated most seriously by avian influenza. The types of poultry might be the factor which influenced the subtype H7 prevalence in poultry markets.