Identifying Areas Suitable for the Occurrence of Rift Valley Fever in North Africa: Implications for Surveillance
Identifying Areas Suitable for the Occurrence of Rift Valley Fever in North Africa: Implications for Surveillance
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DOI：
10.1111/tbed.12331
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发表时间：
2016-12-01
影响因子：
4.3
通讯作者：
Henaux, V.
中科院分区：
文献类型：
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作者：
Arsevska, E.;Hellal, J.;Henaux, V.
裂谷热是一种病媒传播的人畜共患疾病，已在整个非洲和阿拉伯半岛大范围爆发，对以畜牧业为基础的经济和公共卫生造成严重后果。虽然在摩洛哥、阿尔及利亚、突尼斯和利比亚从未有过裂谷热的报告，但由于跨界牲畜流动或受感染的蚊子媒介可能带来病毒，裂谷热是马格里布的一种重点疾病。然而，监测活动和预警应急计划的实施需要更好地了解流行病学情况。我们进行了多标准决策分析，将宿主分布与驱动蚊子数量的重要生态因素相结合，确定裂谷热流行的热点和适当时期（即在较长一段时间内稳定传播在低至中等水平）和裂谷热动物流行事件（即在一个大的地理区域突然出现大量受感染的动物）。我们还利用现有的关于病媒存在和生境偏好的信息模拟了病媒物种分布。我们发现，马格里布北方地区中度适合裂谷热的动物流行，但高度适合裂谷热的动物流行。病媒物种分布模型确定这些地区为最有利的蚊子栖息地。由于动物宿主密度低和干旱条件，除绿洲外，荒漠地区裂谷热适宜性较低。然而，在假定的不适合的地区存在的主管媒介强调需要进一步评估蚊子的栖息地偏好。这项研究每月绘制裂谷热适宜性地图，对参与设计基于风险的监测方案的动物健康管理人员和兽医服务部门很有用。可利用现有的国别信息来源，并通过纳入关于马格里布疾病流行病学和病媒分布的现有知识，进一步加强适宜性地图。
Rift Valley fever (RVF) is a vector-borne zoonotic disease that has caused widespread outbreaks throughout Africa and the Arabian Peninsula, with serious consequences for livestock-based economies and public health. Although there have never been any reports of RVF in Morocco, Algeria, Tunisia and Libya, it is a priority disease in the Maghreb, due to the threat of introduction of the virus through transboundary livestock movements or infected mosquito vectors. However, the implementation of surveillance activities and early warning contingency plans requires better knowledge of the epidemiological situation. We conducted a multicriteria decision analysis, integrating host distribution with a combination of important ecological factors that drive mosquito abundance, to identify hot-spots and suitable time periods for RVF enzootic circulation (i.e. stable transmission at a low to moderate level for an extended period of time) and an RVF epizootic event (i.e. a sudden occurrence of a large number of infected animals over a large geographic area) in the Maghreb. We also modelled vector species distribution using available information on vector presence and habitat preference. We found that the northern regions of the Maghreb were moderately suitable for RVF enzootics, but highly suitable for RVF epizootics. The vector species distribution model identified these regions as the most favourable mosquito habitats. Due to the low density of animal hosts and arid conditions, the desert region showed low RVF suitability, except in oases. However, the presence of competent vectors in putative unsuitable areas underlines the need for further assessments of mosquito habitat preference. This study produced monthly RVF suitability maps useful for animal health managers and veterinary services involved in designing risk-based surveillance programmes. The suitability maps can be further enhanced using existing country-specific sources of information and by incorporating knowledge - as it becomes available - on the epidemiology of the disease and distribution of vectors in the Maghreb.