Talla Cheikh, Diallo Diawo, Dia Ibrahima, Ba Yamar, Ndione Jacques-André, Morse Andrew P, Diop Aliou, Diallo Mawlouth
Unité d'Entomologie Médicale, Institut Pasteur de Dakar, B.P. 220, Dakar, Sénégal.
Laboratoire d'Etudes et de Recherches en Statistiques et Développement, Université Gaston Berger, Saint-Louis, Sénégal.
Parasit Vectors. 2016 Feb 27;9:111. doi: 10.1186/s13071-016-1399-3.
Climatic and environmental variables were used successfully by using models to predict Rift Valley fever (RVF) virus outbreaks in East Africa. However, these models are not replicable in the West African context due to a likely difference of the dynamic of the virus emergence. For these reasons specific models mainly oriented to the risk mapping have been developed. Hence, the areas of high vector pressure or virus activity are commonly predicted. However, the factors impacting their occurrence are poorly investigated and still unknown. In this study, we examine the impact of climate and environmental factors on the likelihood of occurrence of the two main vectors of RVF in West Africa (Aedes vexans and Culex poicilipes) hotspots.
We used generalized linear mixed models taking into account spatial autocorrelation, in order to overcome the default threshold for areas with high mosquito abundance identified by these models. Getis' Gi*(d) index was used to define local adult mosquito abundance clusters (hotspot).
For Culex poicilipes, a decrease of the minimum temperature promotes the occurrence of hotspots, whereas, for Aedes vexans, the likelihood of hotspot occurrence is negatively correlated with relative humidity, maximum and minimum temperatures. However, for the two vectors, proximity to ponds would increase the risk of being in an hotspot area.
These results may be useful in the improvement of RVF monitoring and vector control management in the Barkedji area.
通过使用模型成功利用气候和环境变量预测东非裂谷热（RVF）病毒爆发。然而，由于病毒出现动态可能存在差异，这些模型在西非背景下无法复制。因此，已开发出主要针对风险绘图的特定模型。因此，通常可以预测高媒介压力或病毒活动的区域。然而，对影响其发生的因素研究甚少且仍不清楚。在本研究中，我们研究了气候和环境因素对西非裂谷热两种主要媒介（骚扰伊蚊和波氏库蚊）热点地区发生可能性的影响。
我们使用考虑空间自相关的广义线性混合模型，以克服这些模型确定的高蚊虫丰度地区的默认阈值。Getis的Gi*(d)指数用于定义当地成年蚊虫丰度集群（热点）。
对于波氏库蚊，最低温度的降低会促进热点的出现，而对于骚扰伊蚊，热点出现的可能性与相对湿度、最高和最低温度呈负相关。然而，对于这两种媒介，靠近池塘会增加处于热点地区的风险。
这些结果可能有助于改善巴尔克吉地区裂谷热监测和媒介控制管理。
