Risk Factors of Highly Pathogenic Avian Influenza H5N1 Occurrence at the Village and Farm Levels in the Red River Delta Region in Vietnam
Risk Factors of Highly Pathogenic Avian Influenza H5N1 Occurrence at the Village and Farm Levels in the Red River Delta Region in Vietnam
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DOI：
10.1111/j.1865-1682.2011.01227.x
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发表时间：
2011-12-01
影响因子：
4.3
通讯作者：
Roger, F.
中科院分区：
文献类型：
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作者：
Desvaux, S.;Grosbois, V.;Roger, F.
一项在村庄和农场层面进行的病例对照研究旨在调查 2007 年越南北部一个省份爆发高致病性禽流感 H5N1 的危险因素。收集了 19 个病例村、38 个未匹配对照村以及 19 对匹配农场的人类和自然环境以及家禽生产系统的相关数据。我们的结果证实了家禽运输和贸易活动的作用。特别是，我们的模型发现，村庄中肉鸡数量较多（OR = 1.49，95% CI：1.12-1.96）以及村庄至少有一名家禽贸易商（OR = 11.53，95% CI：1.34-98.86）会增加风险。在我们的两个模型之一中，我们还发现，通常用于水禽生产的池塘和溪流密度的增加以及村里鸭群数量的增加也增加了风险。作为我们研究人群中饲养后院家禽的家庭的指标，饲养家禽的家庭比例较高是一个保护因素（OR = 0.95，95% CI：0.91-0.98）。在农场层面，通过单变量分析确定了 5% I 类误差水平的三个风险因素：禽类总数增加 (P = 0.006)、获得水的鸡群数量增加 (P = 0.027) 以及农场肉鸡群数量增加 (P = 0.049)。由于记录系统较差，很难调查疫苗接种实施的效果（日期和剂量）。由于我们的样本量有限，一些影响有限的保护性或风险因素可能尚未被发现。尽管如此，我们的研究结果使人们更好地了解了越南红河三角洲地区一个省份 HPAI H5N1 的当地传播机制，并强调了减少高风险贸易和生产实践的必要性。
A case-control study at both village and farm levels was designed to investigate risk factors for highly pathogenic avian influenza H5N1 during the 2007 outbreaks in one province of Northern Vietnam. Data related to human and natural environments, and poultry production systems were collected for 19 case and 38 unmatched control villages and 19 pairs of matched farms. Our results confirmed the role of poultry movements and trading activities. In particular, our models found that higher number of broiler flocks in the village increased the risk (OR = 1.49, 95% CI: 1.12-1.96), as well as the village having at least one poultry trader (OR = 11.53, 95% CI: 1.34-98.86). To a lesser extent, in one of our two models, we also identified that increased density of ponds and streams, commonly used for waterfowl production, and greater number of duck flocks in the village also increased the risk. The higher percentage of households keeping poultry, as an indicator of households keeping backyard poultry in our study population, was a protective factor (OR = 0.95, 95% CI: 0.91-0.98). At the farm level, three risk factors at the 5% level of type I error were identified by univariate analysis: a greater total number of birds (P = 0.006), increase in the number of flocks having access to water (P = 0.027) and a greater number of broiler flocks in the farm (P = 0.049). Effect of vaccination implementation (date and doses) was difficult to investigate because of a poor recording system. Some protective or risk factors with limited effect may not have been identified owing to our limited sample size. Nevertheless, our results provide a better understanding of local transmission mechanisms of HPAI H5N1 in one province of the Red River Delta region in Vietnam and highlight the need to reduce at-risk trading and production practices.