Co-occurrence of viruses and mosquitoes at the vectors' optimal climate range: An underestimated risk to temperate regions?
Co-occurrence of viruses and mosquitoes at the vectors' optimal climate range: An underestimated risk to temperate regions?
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DOI：
10.1371/journal.pntd.0005604
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发表时间：
2017-06
影响因子：
3.8
通讯作者：
Baylis M
中科院分区：
文献类型：
--
作者：
Blagrove MSC;Caminade C;Waldmann E;Sutton ER;Wardeh M;Baylis M
据估计，蚊子传播的病毒每年造成1亿多例人类疾病。已经开发了许多方法来帮助确定这些病毒传播风险最大的地区。然而，一般来说，这些方法主要侧重于气候对病媒或其传播的病原体的影响，而不考虑病媒和病毒的最佳条件之间的动态相互作用。在这里，我们使用了一种新的方法，该方法考虑了病毒传播的最佳温度和蚊子媒介的最佳气候之间的复杂相互作用。利用已发表的地理定位数据，我们确定了温度和降雨量范围，其中一些蚊子媒介已被观察到与西尼罗河病毒，登革热病毒或基孔肯雅病毒共同发生。然后，我们研究了是否最佳的气候为共同出现的载体和病毒之间的变化“温暖”和“凉爽”适应载体相同的病毒。我们发现，尽管媒介温度范围存在显着重叠，但不同的蚊子媒介在不同的温度下与相同的病毒共存。具体来说，我们发现，共存与各自的载体的最佳气候条件相关;较冷适应蚊子往往与相同的病毒在较冷的条件下共存，而不是他们的温暖适应同行。我们的结论是，蚊子似乎是最能够传播病毒的蚊子的最佳气候范围内，并假设这可能是由于成比例的过度延长的载体寿命，和其他增加健身属性，在这个最佳范围内。这些结果表明，可能低估了温带地区本地的病媒蚊子物种所构成的威胁，而热带入侵病媒向温带较冷地区移动所产生的威胁可能被高估。蚊子传播的病毒，如登革热，据信每年造成超过1亿例人类疾病。目前旨在预测病毒传播风险的数学模型通常是高度“以蚊子为中心”或“以病毒为中心”的。为了使病毒传播发生，条件需要适合蚊子和病毒：因此，我们提出了一种新的方法，该方法考虑了蚊子和病毒的不同最佳条件之间的相互作用。我们的研究结果表明，适应温暖或寒冷的蚊子分别在温暖或寒冷的气候中是更有效的媒介。因此，我们认为，目前存在低估的风险，温带地区从他们的本地和凉爽的适应蚊子。
Mosquito-borne viruses have been estimated to cause over 100 million cases of human disease annually. Many methodologies have been developed to help identify areas most at risk from transmission of these viruses. However, generally, these methodologies focus predominantly on the effects of climate on either the vectors or the pathogens they spread, and do not consider the dynamic interaction between the optimal conditions for both vector and virus. Here, we use a new approach that considers the complex interplay between the optimal temperature for virus transmission, and the optimal climate for the mosquito vectors. Using published geolocated data we identified temperature and rainfall ranges in which a number of mosquito vectors have been observed to co-occur with West Nile virus, dengue virus or chikungunya virus. We then investigated whether the optimal climate for co-occurrence of vector and virus varies between “warmer” and “cooler” adapted vectors for the same virus. We found that different mosquito vectors co-occur with the same virus at different temperatures, despite significant overlap in vector temperature ranges. Specifically, we found that co-occurrence correlates with the optimal climatic conditions for the respective vector; cooler-adapted mosquitoes tend to co-occur with the same virus in cooler conditions than their warmer-adapted counterparts. We conclude that mosquitoes appear to be most able to transmit virus in the mosquitoes’ optimal climate range, and hypothesise that this may be due to proportionally over-extended vector longevity, and other increased fitness attributes, within this optimal range. These results suggest that the threat posed by vector-competent mosquito species indigenous to temperate regions may have been underestimated, whilst the threat arising from invasive tropical vectors moving to cooler temperate regions may be overestimated. Mosquito-borne viruses, such as dengue, are believed to cause over 100 million cases of human disease annually. Current mathematical models that aim to predict risk of virus transmission are generally either highly “mosquito-centric” or “virus-centric”. For virus transmission to occur, conditions need to be suitable for both mosquito and virus: hence, we propose a novel approach that considers the interplay between the different optimal conditions for the mosquito and the virus. Our findings indicate that warmer- or colder- adapted mosquitoes are significantly more efficient vectors in warmer or colder climates respectively. Consequently, we propose that there is currently an underestimation of risk to temperate regions from their native and cooler adapted mosquitoes.