Landscape attributes driving avian influenza virus circulation in the Lake Alaotra region of Madagascar
Landscape attributes driving avian influenza virus circulation in the Lake Alaotra region of Madagascar
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DOI：
10.4081/gh.2014.33
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发表时间：
2014-05-01
影响因子：
1.7
通讯作者：
Chevalier, Veronique
中科院分区：
文献类型：
--
作者：
Guerrini, Laure;Paul, Mathilde C.;Chevalier, Veronique
虽然高致病性禽流感H5N1病毒的空间格局已在整个东南亚进行了研究，但对非洲禽流感的空间风险因素知之甚少。在本论文中，我们结合血清学数据，从家禽和遥感环境因素在马达加斯加阿劳特拉湖地区，探索禽流感和景观变量之间的任何关联。对2008年和2009年对家禽进行的横断面调查的血清学数据进行了检查，并使用监督分类法对Landsat 7号卫星图像进行了分析。在1公里的缓冲区周围的农舍和距离最近的水体的优势景观特征提取。分析了来自241个鸟群的1 038个个体鸟类血液样本，并使用逻辑回归模型量化了禽流感血清阳性率与这些景观变量之间的关联。没有发现H5或H7禽流感亚型存在的证据，表明只有低致病性禽流感（LPAI）在传播。家禽养殖场周围的三个主要的土地覆盖类：草原萨凡纳，稻田和湿地。发现LPAI血清阳性率与距离最近水体的距离呈显著负相关。我们还发现，LPAI血清阳性率是较高的主要湿地或水稻景观的农场比周围的干燥萨凡纳。这项研究的结果表明，如果高致病性禽流感H5N1病毒被引入马达加斯加，阿劳特拉湖地区的环境条件可能会使病毒传播和持续存在。
While the spatial pattern of the highly pathogenic avian influenza H5N1 virus has been studied throughout Southeast Asia, little is known on the spatial risk factors for avian influenza in Africa. In the present paper, we combined serological data from poultry and remotely sensed environmental factors in the Lake Alaotra region of Madagascar to explore for any association between avian influenza and landscape variables. Serological data from cross-sectional surveys carried out on poultry in 2008 and 2009 were examined together with a Landsat 7 satellite image analysed using supervised classification. The dominant landscape features in a 1-km buffer around farmhouses and distance to the closest water body were extracted. A total of 1,038 individual bird blood samples emanating from 241 flocks were analysed, and the association between avian influenza seroprevalence and these landcape variables was quantified using logistic regression models. No evidence of the presence of H5 or H7 avian influenza subtypes was found, suggesting that only low pathogenic avian influenza (LPAI) circulated. Three predominant land cover classes were identified around the poultry farms: grassland savannah, rice paddy fields and wetlands. A significant negative relationship was found between LPAI seroprevalence and distance to the closest body of water. We also found that LPAI seroprevalence was higher in farms characterised by predominant wetlands or rice landscapes than in those surrounded by dry savannah. Results from this study suggest that if highly pathogenic avian influenza H5N1 virus were introduced in Madagascar, the environmental conditions that prevail in Lake Alaotra region may allow the virus to spread and persist.