PDF(Pubmed)
Abstract：
BACKGROUND: In recent years the Asian bush mosquito Aedes japonicus has invaded Europe, including the Netherlands. This species is a known vector for a range of arboviruses, possibly including West Nile virus (WNV). As WNV emerged in the Netherlands in 2020, it is important to investigate the vectorial capacity of mosquito species present in the Netherlands to estimate the risk of future outbreaks and further spread of the virus. Therefore, this study evaluates the potential role of Ae. japonicus in WNV transmission and spillover from birds to dead-end hosts in the Netherlands.
METHODS: We conducted human landing collections in allotment gardens (Lelystad, the Netherlands) in June, August and September 2021 to study the diurnal and seasonal host-seeking behaviour of Ae. japonicus. Furthermore, their host preference in relation to birds using live chicken-baited traps was investigated. Vector competence of field-collected Ae. japonicus mosquitoes for two isolates of WNV at two different temperatures was determined. Based on the data generated from these studies, we developed a Susceptible-Exposed-Infectious-Recovered (SEIR) model to calculate the risk of WNV spillover from birds to humans via Ae. japonicus, under the condition that the virus is introduced and circulates in an enzootic cycle in a given area.
RESULTS: Our results show that Ae. japonicus mosquitoes are actively host seeking throughout the day, with peaks in activity in the morning and evening. Their abundance in August was higher than in June and September. For the host-preference experiment, we documented a small number of mosquitoes feeding on birds: only six blood-fed females were caught over 4 full days of sampling. Finally, our vector competence experiments with Ae. japonicus compared to its natural vector Culex pipiens showed a higher infection and transmission rate when infected with a local, Dutch, WNV isolate compared to a Greek isolate of the virus. Interestingly, we also found a small number of infected Cx. pipiens males with virus-positive leg and saliva samples.
CONCLUSIONS: Combining the field and laboratory derived data, our model predicts that Ae. japonicus could act as a spillover vector for WNV and could be responsible for a high initial invasion risk of WNV when present in large numbers.
METHODS: We conducted human landing collections in allotment gardens (Lelystad, the Netherlands) in June, August and September 2021 to study the diurnal and seasonal host-seeking behaviour of Ae. japonicus. Furthermore, their host preference in relation to birds using live chicken-baited traps was investigated. Vector competence of field-collected Ae. japonicus mosquitoes for two isolates of WNV at two different temperatures was determined. Based on the data generated from these studies, we developed a Susceptible-Exposed-Infectious-Recovered (SEIR) model to calculate the risk of WNV spillover from birds to humans via Ae. japonicus, under the condition that the virus is introduced and circulates in an enzootic cycle in a given area.
RESULTS: Our results show that Ae. japonicus mosquitoes are actively host seeking throughout the day, with peaks in activity in the morning and evening. Their abundance in August was higher than in June and September. For the host-preference experiment, we documented a small number of mosquitoes feeding on birds: only six blood-fed females were caught over 4 full days of sampling. Finally, our vector competence experiments with Ae. japonicus compared to its natural vector Culex pipiens showed a higher infection and transmission rate when infected with a local, Dutch, WNV isolate compared to a Greek isolate of the virus. Interestingly, we also found a small number of infected Cx. pipiens males with virus-positive leg and saliva samples.
CONCLUSIONS: Combining the field and laboratory derived data, our model predicts that Ae. japonicus could act as a spillover vector for WNV and could be responsible for a high initial invasion risk of WNV when present in large numbers.
摘要：
背景：近年来，亚洲灌木蚊子日本伊蚊入侵欧洲，包括荷兰。该物种是一系列虫媒病毒的已知载体，可能包括西尼罗河病毒（WNV）。随着WNV于2020年在荷兰出现，重要的是调查荷兰存在的蚊子的媒介能力，以估计该病毒未来爆发和进一步传播的风险。因此,本研究评估了Ae的潜在作用。在荷兰，WNV传播和从鸟类到死胡同宿主的溢出。
方法：我们在分配花园中进行了人类登陆收集（Lelystad，荷兰)在6月，2021年8月和9月研究Ae的昼夜和季节性寻找宿主的行为。刺槐.此外，研究了他们对使用活鸡诱饵诱捕器的鸟类的寄主偏好。现场采集Ae的矢量能力。确定了在两个不同温度下WNV的两个分离株的日本蚊子。根据这些研究产生的数据，我们开发了一个易感暴露感染恢复（SEIR）模型，以计算WNV通过Ae从鸟类溢出到人类的风险。日本,在这种情况下，病毒被引入并在给定区域的植物性细胞周期中循环。
结果：我们的结果表明Ae.日本蚊子一整天都在积极寻找宿主，早上和晚上的活动高峰。它们在8月的丰度高于6月和9月。对于主机偏好实验，我们记录了少量以鸟类为食的蚊子:在整整4天的采样中，只有6只吸血的雌性被捕获。最后,我们对Ae的矢量能力实验。日本与其天然媒介淡色库蚊相比，当感染局部时显示出更高的感染和传播率，荷兰人,WNV分离株与希腊分离株的病毒相比。有趣的是,我们还发现了少量感染的Cx。有病毒阳性腿和唾液样本的pipiens男性。
结论：结合现场和实验室衍生数据，我们的模型预测Ae。japonicus可以充当WNV的溢出载体，并且当大量存在时，可能是WNV的高初始入侵风险的原因。
方法：我们在分配花园中进行了人类登陆收集（Lelystad，荷兰)在6月，2021年8月和9月研究Ae的昼夜和季节性寻找宿主的行为。刺槐.此外，研究了他们对使用活鸡诱饵诱捕器的鸟类的寄主偏好。现场采集Ae的矢量能力。确定了在两个不同温度下WNV的两个分离株的日本蚊子。根据这些研究产生的数据，我们开发了一个易感暴露感染恢复（SEIR）模型，以计算WNV通过Ae从鸟类溢出到人类的风险。日本,在这种情况下，病毒被引入并在给定区域的植物性细胞周期中循环。
结果：我们的结果表明Ae.日本蚊子一整天都在积极寻找宿主，早上和晚上的活动高峰。它们在8月的丰度高于6月和9月。对于主机偏好实验，我们记录了少量以鸟类为食的蚊子:在整整4天的采样中，只有6只吸血的雌性被捕获。最后,我们对Ae的矢量能力实验。日本与其天然媒介淡色库蚊相比，当感染局部时显示出更高的感染和传播率，荷兰人,WNV分离株与希腊分离株的病毒相比。有趣的是,我们还发现了少量感染的Cx。有病毒阳性腿和唾液样本的pipiens男性。
结论：结合现场和实验室衍生数据，我们的模型预测Ae。japonicus可以充当WNV的溢出载体，并且当大量存在时，可能是WNV的高初始入侵风险的原因。
