Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou 310051, China;
First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China.
J Thorac Dis. 2013 Dec;5(6):790-6. doi: 10.3978/j.issn.2072-1439.2013.12.45.
The first outbreak of H5N1 highly-pathogenic avian influenza (HPAI) virus associated with several human deaths occurred in 1997 in Hong-Kong, China. While H5N1 virus infection in poultry workers has been studied in some detail, little is known about the environmental risk factors of the H5 avian influenza virus infection in China.
A cross-sectional study was performed to evaluate the environmental load of H5 viruses in poultry-contaminated environments and to explore potential risk factors associated with infection in poultry workers between October 2010 and March 2012. Serum and environmental samples were collected in Zhejiang province, China. The hemagglutination inhibition (HI) assay was used to analyze human sera for antibodies against H5N1 virus [A/Hubei/1/2010 (H5N1) and A/Anhui/1/2005 (H5N1)]. All participants were interviewed with a standardized questionnaire to collect information on exposure to poultry. H5 Avian influenza virus in the environmental samples was detected by real time RT-PCR.
One hundred and five of 3,453 environmental samples (3.0%) tested positive for H5 avian influenza virus. Fifty-five of 1,169 subjects (4.7%) tested seropositive for anti-H5N1 antibodies. A statistically significant difference in H5 virus detection rate was found among the different environments sampled (<0.001), with the highest showed in live bird markets (68.6%). Detection rate varied according to the source of samples, sewage (9.5%), drinking water (19.0%), feces (19.0%), cage surface (25.7%), and slaughtering chopping boards (15.2%), respectively. Direct or close contact with poultry (OR =5.20, 95% CI, 1.53-17.74) and breeding numerous poultry (OR =3.77, 95% CI, 1.72-8.73) were significantly associated with seroprevalence of antibodies to avian influenza virus A (H5N1).
The number of birds bred more than 1,000 and direct or close contact with poultry in the workplace or the environment would be a potential risk of H5N1 infection.
1997 年在中国香港首次爆发了与多人死亡有关的 H5N1 高致病性禽流感（HPAI）病毒。虽然已经对家禽工人中的 H5N1 病毒感染进行了一些详细研究，但对中国 H5 禽流感病毒的环境危险因素知之甚少。
本研究于 2010 年 10 月至 2012 年 3 月期间在中国浙江省进行了一项横断面研究，以评估家禽污染环境中的 H5 病毒的环境负荷，并探索与家禽工人感染相关的潜在危险因素。采集血清和环境样本。采用血凝抑制（HI）试验分析人血清中针对 H5N1 病毒（A/Hubei/1/2010 [H5N1]和 A/Anhui/1/2005 [H5N1]）的抗体。对所有参与者进行了标准化问卷调查，以收集有关接触家禽的信息。采用实时 RT-PCR 检测环境样本中的 H5 禽流感病毒。
在所检测的 3453 个环境样本中，有 105 个（3.0%）检测出 H5 禽流感病毒呈阳性。在 1169 名研究对象中，有 55 名（4.7%）血清抗 H5N1 抗体呈阳性。不同采样环境中 H5 病毒检出率存在显著差异（<0.001），活禽市场最高（68.6%）。根据样本来源，检测率分别为污水（9.5%）、饮用水（19.0%）、粪便（19.0%）、笼面（25.7%）和屠宰砧板（15.2%）。与家禽的直接或密切接触（OR=5.20，95%CI，1.53-17.74）和大量养殖家禽（OR=3.77，95%CI，1.72-8.73）与禽流感病毒 A（H5N1）的血清抗体阳性率显著相关。
养殖鸟类超过 1000 只，以及在工作场所或环境中与家禽直接或密切接触，可能是 H5N1 感染的潜在风险。
