中国云南湄公河上游乙型脑炎传播媒介生物学及行为的研究(英文)

THE BIOLOGY AND BEHAVIOUR OF JAPANESE ENCEPHALITIS VECTORS IN THE HUMAN HOUSES IN THE UPPER VALLEY OF THE MEKONG RIVER IN YUNNAN, P.R. CHINA

目的探讨乙型脑炎病毒媒介在人房的季节消长、嗜血习性和叮人行为,以及其幼虫相关的生物学习性, 从而制定出有效的媒介控制措施. 方法 2001年6～12月,在云南南部湄公河上游,选取一个种植场,采用CDC 诱蚊灯和人工诱捕的方法捕蚊;蚊胃血源环状沉淀法鉴定其嗜血习性以及孳生地调查幼虫孳生习性. 结果共捕获乙脑病毒媒介蚊虫5属、11种、5 726只.无论是诱蚊灯还是人工诱蚊法,三带喙库蚊、伪杂鳞库蚊、棕头库蚊和中华按蚊的季节密度高峰都出现于6～8月的雨季;3种库蚊在村内和村外有整夜叮咬活动,但中华按蚊的叮人高峰出现在21:00 之前.人房室内诱蚊灯捕蚊与室外人诱观察发现,室内捕捉乙脑病媒数量远高于室外.蚊胃血检测结果发现它们的人血指数都比较高;幼虫具有明显的特征性分布. 结论湄公河上游地区人房优势蚊种三带喙库蚊、伪杂鳞库蚊、棕头库蚊和中华按蚊的生物学及行为与以往畜圈调查的结果存在着差异.

Objective To study the seasonal abundance, host preference and patterns of biting activity in houses, and larval biology of Japanese Encephalitis(JE) vectors, so as to develop effective control measures. Methods From June to December 2001, choosing one plantation in the upper valley of the Mekong River in the south of Yunnan, Centres for Disease Control (CDC) light trap and human landing methods were used to capture mosquitoes, blood meal samples were tested by the precipitin method and biologic habits of immature stages were investigated for their breeding sites. Results A total of 5 726 JE vector mosquitoes of 11 species of 5 genera were collected from a plantation in the upper valley of the Mekong River. Peaks in the population densities of Culex tritaeniorhynchus, Cx. pseudovishnui, Cx. fuscocephala and Anopheles sinensis were in the rainy season from June to August, by both light trap and human landing catches. Biting activity of these three Culex mosquitoes, both in and outside plantation, began after sunset and maintained through the night. But the An. sinensis biting peak was before 21:00 hours. Comparison of the efficacy of mosquito collection by light trap in houses with that out of doors by human landing catches, showed that the indoor catches of JE vectors were higher than that out of doors. Analysis of mosquito blood meals showed that their human blood indices were high. Larvae had characteristic distributions in relation to the plantation. Conclusion All of these finds suggested that in the upper valley of Mekong River, Cx. tritaeniorhynchus, Cx. pseudovishnui, Cx. fuscocephala and An. sinensis are different on the biologics and behaviours in comparison with those of previous studies in animal sheds.