Wang Ying, Kong Wen-hua, Zhu Hong-hao, Luo Tong-yong, Lin Xin-ming, Yu Bin, Chen Bang-hua, Hu Quan, Peng Jin-song
Virus Laboratory, Wuhan Centres for Disease Prevention and Control, Wuhan 430015, China.
Zhonghua Yu Fang Yi Xue Za Zhi. 2011 Dec;45(12):1082-5.
To survey the distribution of influenza A subtypes in external environment and investigate the infectious status of highly pathogenic avian influenza (H5N1) in poultry-exposed population in Wuhan.
Seventy-eight external environmental samples (water, cage surface and fecal samples) were collected from 3 habitats of wild migratory birds and 5 urban live-poultry markets in 2010. In 13 avian influenza monitoring points, 249 serum samples were collected from people living around habitats of wild migratory birds or working in live poultry markets. Real-time RT-PCR method was adopted to detect influenza A virus from external environmental samples; and multiple RT-PCR method and specific H3, H5, H7 and H9 primers were then applied to analyze the subtypes of the positive samples. The levels of H5N1 antibody in poultry-exposed population were tested by horse hemagglutination inhibition test and two avian influenza inactivated antigens: A/Hubei/1/10 and A/Anhui/1/05.
Of the 50 external environmental samples collected from live poultry markets, 17 samples were determined to be influenza A virus positive (positive rate 34.0%), including specific subtypes as follows: 4 samples of H5 single-positive subtype, 3 samples of H9 single-positive subtype, 4 samples of H3 and H5 mixed-positive subtype, 2 samples of H3 and H9 mixed-positive subtype, 2 samples of H5 and H9 mixed-positive subtype, 2 samples of H3, H5 and H9 mixed-positive subtype, but no H7 positive subtype was found. The 28 external environmental samples collected from habitats of wild migratory birds were all influenza A virus negative. Considering different types of external environmental samples, the influenza A virus positive rates in water, cage surface and fecal samples were 37.5% (6/16), 16.7% (5/30) and 18.8% (6/32), respectively. There were total 100 samples of serum whose A/Hubei/1/10 antigen inhibiting titers ≥ 40, accounting for 40.2%; while 36 samples of serum (14.5%) whose A/Anhui/1/05 antigen inhibiting titers ≥ 40 were found. The difference had statistical significance (χ(2) = 41.433, P < 0.05). Among the 249 serum samples collected from poultry-exposed population, 5 samples were H5N1 antibody positive against A/Hubei/1/10 antigen (inhibition titer ≥ 160), which came from 4 different live poultry markets, however, no positive serum sample against A/Anhui/1/05 antigen was found.
Multiple subtypes of avian influenza virus simultaneously prevailed in Wuhan urban poultry markets. Moreover, results from the distribution of avian influenza virus in external environment were consistent with the level of H5N1 antibody in poultry-exposed population.
调查武汉市外环境中甲型流感病毒亚型分布情况，了解家禽暴露人群高致病性禽流感（H5N1）感染状况。
2010年从3个野生候鸟栖息地和5个城市活禽市场采集78份外环境样本（水、笼具表面及粪便样本）。在13个禽流感监测点，采集249份来自野生候鸟栖息地周边居民或活禽市场从业人员的血清样本。采用实时荧光定量RT-PCR方法检测外环境样本中的甲型流感病毒；对阳性样本应用多重RT-PCR方法及特异性H3、H5、H7和H9引物分析其亚型。采用血凝抑制试验，使用两种禽流感灭活抗原A/湖北/1/10和A/安徽/1/05检测家禽暴露人群H5N1抗体水平。
在活禽市场采集的50份外环境样本中，17份样本检测为甲型流感病毒阳性（阳性率34.0%），具体亚型如下：H5单阳性亚型4份，H9单阳性亚型3份，H3和H5混合阳性亚型4份，H3和H9混合阳性亚型2份，H5和H9混合阳性亚型2份，H3、H5和H9混合阳性亚型2份，未发现H7阳性亚型。从野生候鸟栖息地采集的28份外环境样本均为甲型流感病毒阴性。不同类型外环境样本中，水、笼具表面及粪便样本的甲型流感病毒阳性率分别为37.5%（6/16）、16.7%（5/30）和18.8%（6/32）。共有100份血清样本A/湖北/1/10抗原抑制效价≥40，占40.2%；发现36份血清样本（14.5%）A/安徽/1/05抗原抑制效价≥40。差异有统计学意义（χ(2)=41.433，P<0.05）。在家禽暴露人群采集的249份血清样本中，5份样本针对A/湖北/1/10抗原H5N1抗体阳性（抑制效价≥160），分别来自4个不同的活禽市场，未发现针对A/安徽/1/05抗原的阳性血清样本。
武汉市城区活禽市场同时存在多种亚型禽流感病毒流行。外环境禽流感病毒分布情况与家禽暴露人群H5N1抗体水平结果一致。
