云南景东县乙型脑炎流行状况调查

目的调查云南省景东县流行性乙型脑炎的流行现状。方法媒介蚊虫调查采用诱蚊灯通宵捕蚊方法,蚊虫乙脑病毒检测采取RT-PCR方法,健康人群血清乙脑病毒抗体检测采用ELISA。结果共采集到蚊虫4属15种6653只,其中三带喙库蚊和中华按蚊属于当地的优势种群,分别占总捕获蚊数的82.07%和10.46%。RT-PCR检测三带喙库蚊和中华按蚊共16批1310只,各有1株感染乙脑病毒;ELISA检测当地健康人群血清乙脑病毒抗体阳性率为72.96%,不同年龄组人群乙脑病毒抗体水平差异有统计学意义(χ2=51.589,P0.01)。结论云南景东县蚊虫种类较多,三带喙库蚊和中华按蚊有传播乙型脑炎的作用。     

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

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。     

老挝波乔会晒县和敦蓬县居民区蚊虫种类调查

目的调查老挝波乔省会晒县和敦蓬县居民区成蚊种类组成,为制定当地媒介控制措施提供依据。方法采用诱蚊灯通宵捕蚊法和电动捕蚊器法采集成蚊,采用形态学方法鉴定蚊虫种类。结果共捕获蚊虫3亚科7属38种13 537只,乙型脑炎媒介三带喙库蚊和棕头库蚊属于当地优势蚊种,分别占捕获总数的75.57%(10 230/13 537)和13.61%(1 843/13 537);疟疾媒介中华按蚊和登革热媒介白纹伊蚊分别占捕获总数的0.57%(77/13 537)和0.94%(127/13 537)。结论老挝波乔省会晒县和敦蓬县蚊虫种类丰富,乙型脑炎媒介三带喙库蚊、疟疾媒介中华按蚊和登革热媒介白纹伊蚊广泛存在,提示当地存在乙型脑炎、登革热、疟疾等重要虫媒传染病流行的风险,当地应加强对上述媒介蚊虫的监测。     

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

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、5726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。     

孟加拉国吉大港兰加马蒂蚊类群落特征调查

目的了解孟加拉国兰加马蒂蚊类种群群落特征,为当地媒介蚊虫控制措施的制定提供依据。方法 2019年9月,在孟加拉国兰加马蒂人房和牛房采用诱蚊灯通宵诱捕成蚊,形态鉴定蚊种并分析其群落特征。结果共捕获蚊虫2亚科7属33种6 445只,当地的优势蚊种为菲律宾按蚊和三带喙库蚊,分别占捕获蚊总数的37.66%(2 427/6 445)和35.67%(2 299/6 445)。人房致倦库蚊构成比较高,为73.59%(719/977);牛房菲律宾按蚊占41.73%(282/5 468),三带喙库蚊占41.04%(2 244/5 468)。蚊虫Shannon-Wienner多样性指数为1.62,Simpson多样性指数为0.29,Pielou均匀度指数0.46。结论孟加拉国兰加马蒂蚊虫种类丰富,疟疾和乙型脑炎媒介蚊虫属于当地优势蚊虫种群。应进一步加强孟加拉国蚊虫群落特征研究,为当地媒介蚊虫控制措施的制定提供参考依据。     

云南省思茅市倚象镇人房蚊类群落特征调查

目的对思茅市翠云区倚象镇纳吉村人房蚊类进行调查,了解蚊类群落学特征,为蚊媒疾病防制提供科学依据。方法采用CDC诱蚊灯在人房通宵捕蚊,对所获蚊虫进行群落学特征分析。结果捕获2亚科、6属、9亚属、26种696只蚊虫,数据分析发现人房蚊虫优势种为棕头库蚊和三带喙库蚊,优势度分别为62·06、27·23。结论当地人房群落蚊种较多,群落组成和结构复杂。     

甘肃省庆阳市媒介蚊虫类携带病毒调查

目的了解甘肃省庆阳市区域媒介蚊虫类分布特点及携带病毒情况,为防控虫媒病毒相关疾病提供科学依据。方法采用电子诱蚊灯、捕虫网诱捕,并进行分类;用细胞培养法分离病毒,用血清学分子生物学方法进行病毒鉴定。结果2012年捕获蚊虫5种,4238只,其中淡色库蚊2459只,占58．0％;中华按蚊794只,占18．73％;三带喙库蚊652只,占15．38％;刺扰伊蚊215只,占5．08％;济南按蚊118只,占2．8％;捕获的三带喙库蚊中分离出1株盖塔病毒,淡色库蚊检出6株库蚊黄病毒。结论淡色库蚊是庆阳市区域的优势蚊种,蚊虫携带黄病毒和盖塔病毒等虫媒病毒,应加大对该地区蚊虫及虫媒病毒的监测、调查、研究及防治工作。     

济宁市太白湖湿地蚊媒季节消长及2种监测工具应用效果

目的 调查济宁市太白湖湿地蚊媒季节消长水平,比较功夫小帅诱蚊灯和WJ?C全自动高效蚊虫采样器的诱蚊效果。方法 2017年6-10月分别采用人饵帐诱捕蚊法、功夫小帅诱蚊灯、WJ?C全自动高效蚊虫采样器诱捕蚊媒,对太白湖湿地的成蚊种类、季节消长等情况进行调查分析。结果 人饵帐诱捕蚊法共捕获成蚊10 914只,包括5属13种;三带喙库蚊、淡色库蚊和常型曼蚊为当地的优势蚊种,三者占捕蚊总数的77.41%;黄色柯蚊比例明显上升。各种成蚊均于6月开始出现,7-8月为活动高峰期。2种诱蚊工具均有较好的诱捕效果,WJ?C全自动高效蚊虫采样器诱蚊效果与人饵帐诱法基本一致;诱蚊灯对常型曼蚊和黄色柯蚊的诱捕效果明显低于人饵帐诱法。结论 济宁市太白湖湿地蚊虫结构有所变化,应加强监测。诱蚊灯和WJ?C全自动高效蚊虫采样器均具有较好的诱蚊效果,但各有优劣,监测过程中应注意监测方法的一致性。     

云南楚雄2014年蚊媒及其病毒感染调查

目的了解云南楚雄元谋、武定和双柏3县蚊虫及其主要虫媒病毒种类,为制定出有效的虫媒传染病防控对策提供依据。方法2014年6-7月采用诱蚊灯在调查点通宵捕捉蚊虫,对现场采集蚊虫进行形态分类鉴定;采用C6/36细胞培养法和RT-PCR扩增目的基因片段对蚊虫体内病毒进行分离、鉴定。结果共捕获4属15种12 384只蚊虫,三带喙库蚊、中华按蚊、致倦库蚊和微小按蚊分别占捕获蚊虫总数的59.95%、19.31%、10.90%和 4.13%;C6/36细胞培养处理116组蚊虫,其中29组发生细胞病变,经基因鉴定为版纳病毒(BAV)、Totivirus 病毒(TOV)、乙型脑炎病毒(JEV)和Nam Dinh病毒(NDiV)4种,其中,三带喙库蚊的JEV、BAV、TOV和NDiV基因扩增批阳性率分别为1.87%、11.32%、3.77%和9.43%;希氏库蚊的NDiV基因扩增批阳性率为25.00%;致倦库蚊和中华按蚊的BAV、NDiV批阳性率分别为20.00%、33.34% 和5.00%、7.50%。结论楚雄地区蚊虫种类多,且以三带喙库蚊和中华按蚊为优势蚊种,从两种蚊虫标本中能分离到JEV、TOV、BAV和NDiV病毒,表明调查地区发生乙脑及其它虫媒病毒性疾病流行的危险较大。     

南京市2013年蚊虫密度、种群及季节消长情况分析

目的了解南京市2013年蚊虫密度、种群及季节消长情况。方法按照《全国病媒生物监测方案（试行）》要求,采用诱蚊灯法在南京市开展蚊虫监测。结果 2013年南京市共捕蚊3 268只,蚊密度为0.57只/（h·灯）,捕获的蚊虫隶属2亚科4属5种,优势蚊种为淡色库蚊和三带喙库蚊,分别约占58.05%和17.59%,季节消长呈7月和10月双高峰曲线。结论南京市蚊虫具有种群多样性,淡色库蚊和三带喙库蚊为优势蚊种,每年7月和10月为密度高峰季节,可供当地蚊虫防制措施的指定提供参考。同时要关注蚊虫孳生地情况及气象因素对蚊虫密度的影响。     

First isolation of Japanese encephalitis from Culex quinquefasciatus in Thailand

Isolation of Japanese encephalitis (JE) virus using C6/36 cell and immunofluorescence virus antigen detection techniques was attempted from female mosquitoes collected with CDC gravid traps in Samut Songkhram Province in the central region and in Phuket Province in southern Thailand, in 2003. One thousand and eighty female mosquitoes including 6 species of the Culicidae family (Culex quinquefasciatus, Cx. gelidus, Cx. tritaeniorhynchus, Cx. whitmorei, Cx. vishnui complex, Cx. s.g. culiciomyia) (pooled by specific specimen), were processed for virus isolation. Two pools of Cx. quinquefasciatus yielded a JE virus isolation. This represents the first report of JE virus isolation from Cx. quinquefasciatus in Thailand.     

Correlation of population indices of female Culex tritaeniorhynchus with Japanese encephalitis viral activity in Kapuk, Indonesia

Nineteen consecutive monthly light trap collections of mosquitoes were made between October 1978 and April 1980 in Kapuk, Indonesia. Kapuk is a small suburb of Jakarta where pigs are raised in close proximity to rice paddies which are breeding sites for Culex tritaeniorhynchus. Japanese encephalitis (JE) virus is believed to be endemic and has been recovered from mosquitoes and pigs in the area on several occasions. A total of 18,435 female Cx. tritaeniorhynchus were allocated to 359 pools of approximately 50 per pool. Virus isolations were attempted in both Vero and BHK-21 cells and agents producing cytopathic effect were identified in a micro-neutralization test. Nineteen strains of JE were recovered from the 359 pools of Cx. tritaeniorhynchus tested. The light trap index of female Cx. tritaeniorhynchus (X) and the relative frequency of pools positive for JE (Y) for each month of the study were plotted and correlation coefficients (r) calculated after transforming the mosquito population data logarithmically and the relative frequencies of isolation by arcsine square root. The close fit of the data (p less than 0.001) to an inverse linear model (1/y = a + b log10X) suggests a close dependence of JE viral activity on the population dynamics of Cx. tritaeniorhynchus. Three additional strains of JE were recovered from other Culex spp. at the same study site. One strain each was isolated from individual pools of Cx. gelidus, Cx. vishnui and Cx. fuscocephala. Cx. tritaeniorhynchus was more frequently infected with JE than the other species tested.     

云南省西双版纳州蚊虫分布特点及与虫媒病毒的关系

１９８１、１９８２、１９８３、１９８６、１９８７和１９８８年在西双版纳州景洪、勐海和勐腊县（市）捕获成年雌性蚊虫８属３４种３４５０８只。夜晚在农村畜圈及其周围采获蚊虫２１种,优势蚊种为棕头库蚊和三带喙库蚊;白天在野外竹林采获蚊虫２５种,优势蚊种为贺斑伊蚊和白蚊伊蚊。从三带喙库蚊（８株）、霜背库蚊（４株）、伪杂鳞库蚊（３株）、环带库蚊（１株）、棕头库蚊（１株）、中华按蚊（３株）、刺扰伊蚊（２株）、白     

Longitudinal studies in South Indian villages on Japanese encephalitis virus infection in mosquitoes and seroconversion in goats

Japanese encephalitis (JE) is endemic in Cuddalore district, Tamil Nadu, where Culex tritaeniorhynchus Giles was the major vector. We screened 45 100 adult female Cx. tritaeniorhynchus (902 pools) by enzyme-linked immunosorbent assay and isolated and confirmed JE virus (JEV) by using an insect bioassay system. We had 69 isolates of which 62 (90%) were identified as JEV. The average vector abundance per man hour for Cx. tritaeniorhynchus was 324.5 per month for the period June 1998-May 2000. The average minimum infection rate (MIR) per month in Cx. tritaeniorhynchus was 1.4 (range 0.0-5.6). Every year, a new batch of goats, 20 in the first year and 31 in the second year, born during the non-JE transmission period (January-June), aged <6 months and negative for haemagglutination inhibition (HI) antibodies were procured and placed in the villages as sentinels. Fortnightly, blood specimens were collected from these goats and tested for JE antibodies by HI test. Seroconversions (SCs) were recorded in 14 goats (70%) in the first year and 23 goats (74%) in the second year. JE HI antibody titres in goats were low (1:10-1:80) and these levels declined to undetectable levels in about 4 weeks following SCs. The time sequence of events indicated that four of five peaks of MIR in mosquitoes were followed 1-3 months later by peaks in the proportion of seroconverted goats. We suggest the screening of goats and cattle as a more feasible tool to stratify areas according to JE infection risk to the human population through the regular health system rather than screening mosquitoes using monoclonal antibodies, which is possible only in specialized laboratories.     

Mosquito blood feeding patterns as a factor in the epidemiology of Japanese encephalitis in southern India.

Determinations were made of the source of 16,330 bloodmeals from 10 species of Culex mosquitoes, including recognized vectors of Japanese encephalitis (JE) virus, in two epidemiologically distinct areas in southern India. In Madurai, where cases occurred sporadically and pigs were reared only in some villages, Cx. tritaeniorhynchus, Cx. pseudovishnui, and Cx. vishnui had fed predominantly on cattle (89.2-91%), but less frequently on humans (2.1-6.2%) and on pigs and ardeid birds (0-0.1%). In Nallur, which was endemic for JE and had a large pig population, 4.4-5.4% of the feedings were on these hosts. Cattle feedings accounted for 84.6-88% of the total feedings, human feedings for 2.4-6.2%, but there were no ardeid-positive feedings. Culex tritaeniorhynchus and Cx. vishnui showed a marked increase in the proportion of human feedings during the hot season, due to increased availability of humans sleeping outdoors to mainly exophagic mosquitoes. Feeding indices were corrected for spatial and temporal concurrence of hosts in each season, but these factors were found to require further elucidation. Discrepancies in the relative abundance of vectors as monitored by two different methods are discussed in the light of these observations.     

Short report: observations on the multiple feeding behavior of Culex tritaeniorhynchus (Diptera: culicidae), the vector of Japanese encephalitis in Kerala in southern India

A study was undertaken in villages endemic for Japanese encephalitis (JE) in Kerala in southern India during the period 1998-2001 to determine the host-feeding pattern of Culex tritaeniorhynchus, the major vector of JE in southeast Asia. A total of 3,067 blood-engorged Cx. tritaeniorhynchus were tested and 2,553 (82.2%) of the samples could be identified. Culex tritaeniorhynchus had fed mainly (56.6%) on cattle. Pig feeding accounted 6.3% of the total samples. Some samples (n = 980, 38.3%) were of serologic mixed origin. Of 980 mixed blood-fed mosquitoes, 975 (99.5%) had imbibed blood from two distinct hosts and 5 (0.5%) imbibed blood from three distinct hosts. Mixed blood meals were mostly (96.7%) from cattle and goats. The epidemiologic implications of multiple feeding of Cx. tritaeniorhynchus on dampening (dead-end) hosts such as cattle and goats in the transmission of JE virus is discussed.