Ciećkiewicz Anna M, Ettlin Julia, Veronesi Eva, Marti Andrea, Garcia-Nicolas Obdulio, Hauri Jeannine, Summerfield Artur, Mathis Alexander, Verhulst Niels O
National Centre for Vector Entomology, Institute of Parasitology, Vetsuisse and Medical Faculty, University of Zürich, Switzerland.
Institute of Microbiology, Department of Environment Constructions and Design, University of Applied Sciences and Arts of Southern Switzerland (SUPSI), Mendrisio, Switzerland.
Curr Res Parasitol Vector Borne Dis. 2025 Jul 31;8:100302. doi: 10.1016/j.crpvbd.2025.100302. eCollection 2025.
The Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus endemic to much of Asia and the Western Pacific, both temperate and tropical regions. Globalisation and the expansion of invasive mosquito species raise concerns about their potential establishment in Europe and other currently non-endemic regions. However, limited knowledge exists regarding the vector competence of European mosquitoes, particularly under the region's characteristic fluctuating temperatures. While species are primary JEV vectors, the role of mosquitoes remains unclear. This study assessed the vector competence of field-caught or low-generation colony-derived , , and from Switzerland under a fluctuating temperature regime (16-28 °C), using as a reference. Mosquitoes were exposed to JEV genotype I-b and incubated for 7 and 14 days. RT-qPCR was used to analyse mosquito body parts and saliva to determine infection, dissemination, transmission rates and transmission efficiency. , , and were competent vectors. showed the highest infection rate (13.6%, 9/66) compared to (3.0%, 3/101) and (6.9%, 7/101), while was refractory (0/80). Dissemination was observed in already 7 days post-exposure, preceding other species. had the highest transmission rate (66.7%, 2/3) and efficiency (6.1%, 2/33). This study demonstrates that European mosquitoes can serve as JEV vectors under fluctuating temperatures and may contribute to virus transmission despite being considered secondary vectors. The findings emphasise that species-specific assessments under realistic temperatures are essential in evaluating the risk of JEV establishment in temperate regions.
日本脑炎病毒（JEV）是一种由蚊子传播的黄病毒，在亚洲大部分地区以及西太平洋的温带和热带地区均有流行。全球化和入侵蚊虫物种的扩张引发了人们对其在欧洲和其他目前非流行地区潜在定殖的担忧。然而，关于欧洲蚊子的媒介能力，尤其是在该地区典型的波动温度条件下，我们了解得还很有限。虽然某些物种是JEV的主要传播媒介，但其他蚊子的作用仍不明确。本研究评估了在波动温度范围（16 - 28°C）下，从瑞士野外捕获或低代殖民地饲养的某些蚊子作为日本脑炎病毒媒介的能力，并以另一种蚊子作为参照。将蚊子暴露于JEV基因型I - b，孵育7天和14天。使用RT - qPCR分析蚊子身体部位和唾液，以确定感染、传播、传播率和传播效率。某些蚊子是有效的传播媒介。与另一种蚊子（3.0%，3/101）和第三种蚊子（6.9%，7/101）相比，第一种蚊子显示出最高的感染率（13.6%，9/66），而第四种蚊子不具有易感性（0/80）。在暴露后7天就观察到第一种蚊子有病毒传播，早于其他物种。第一种蚊子具有最高的传播率（66.7%，2/3）和传播效率（6.1%，2/33）。本研究表明，欧洲的某些蚊子在波动温度下可作为JEV的传播媒介，尽管被认为是次要媒介，但仍可能有助于病毒传播。研究结果强调，在实际温度下进行物种特异性评估对于评估JEV在温带地区定殖的风险至关重要。
