Background & objectives: Aedes vittatus (Bigot), an anthropophilic mosquito, plays an important role in the maintenance and transmission of yellow fever (YF), dengue (DEN), chikungunya (CHIKV) and Zika (ZIK) viruses in Africa. In India, though natural isolation of none of these viruses was reported from the mosquito, experimental studies have shown vector competence to DEN and CHIK viruses. Despite wide prevalence in India, their potential in transmitting viruses of public health importance viz., Japanese encephalitis (JEV), West Nile (WNV), Chandipura (CHPV), Chittoor (CHITV) etc., has never been investigated. The objective of the present study is to determine the vector potential of the mosquito to these viruses.
Methods: Mosquitoes were infected by intra-thoracic inoculation as well as by oral feeding, and growth kinetics was determined. Virus dissemination to organs was investigated by determining virus in the harvested organs on specified days’ post infection (PI). Vector competence was determined by detecting the virus in saliva.
Results: Intra thoracic inoculation has shown vector competence of the mosquito to JEV, WNV, CHIV and CHPV. However, using the oral route of infection, replication was observed with only WNV, JEV and CHITV. High degree of WNV replication (6.7log TCID₅₀/ml) with rapid dissemination to wings, legs and salivary glands was seen from 5^th day PI onwards. WNV was detected in saliva with a titer of 0.7log₁₀ TCID₅₀/ml on 5^th day PI. JEV and CHITV replicated in the mosquito yielding 3log and 4log₁₀ TCID₅₀/ml on 5^th and 10^th day PI respectively, but virus was not detected in saliva till 15^th day PI.
Interpretation & conclusion: From the results it is difficult to indict the mosquito as a vector of the viruses studied. However, presence of WNV in saliva of the mosquito shows its potential as a bridge vector and poses a concern especially when virulent WNV strains are circulating in the country.

中文翻译：

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来自印度的伊蚊 (Bigot) 蚊对日本脑炎、西尼罗河、昌迪普拉和奇图病毒的载体能力

背景与目的：伊蚊(Bigot) 是一种嗜人蚊子，在非洲黄热病 (YF)、登革热 (DEN)、基孔肯雅热 (CHIKV) 和寨卡 (ZIK) 病毒的维持和传播中发挥着重要作用。在印度，虽然没有从蚊子中自然分离出这些病毒的报道，但实验研究表明载体对 DEN 和 CHIK 病毒具有能力。尽管在印度广泛流行，但从未研究过它们传播具有公共卫生重要性的病毒的潜力，即日本脑炎 (JEV)、西尼罗河 (WNV)、钱迪普拉 (CHPV)、奇图 (CHITV)等。本研究的目的是确定蚊子对这些病毒的载体潜力。
方法：蚊子通过胸腔内接种和经口进食感染，并测定其生长动力学。通过在感染后指定天数 (PI) 确定收获器官中的病毒来研究病毒向器官的传播。通过检测唾液中的病毒来确定载体能力。
结果：胸腔内接种显示蚊子对 JEV、WNV、CHIV 和 CHPV 具有载体能力。然而，使用口服感染途径，仅观察到 WNV、JEV 和 CHITV 的复制。从PI 的^第5天开始，观察到高度 WNV 复制（6.7log TCID ₅₀ /ml）并快速传播到翅膀、腿和唾液腺。在唾液中检测到 WNV，滴度为 0.7log ₁₀ TCID ₅₀/ml 在^第5天 PI。JEV和CHITV复制在蚊子产生3log和4log ₁₀ TCID ₅₀ 5 / ml的^日和10^日分别天PI，但在唾液直到15中未检测到病毒^个天PI。
解释与结论：从结果来看，很难将蚊子定性为所研究病毒的载体。然而，蚊子唾液中 WNV 的存在显示了其作为桥梁载体的潜力，并引起了人们的关注，尤其是当该国传播有毒 WNV 毒株时。