陕西省流行性乙型脑炎高发区三带喙库蚊的抗药性研究

目的了解陕西省流行性乙型脑炎（乙脑）高发区三带喙库蚊对常用杀虫剂的抗药性水平。方法采用人工小时法调查蚊虫密度;采用区分剂量法测定5种杀虫剂对三带喙库蚊幼虫的24h死亡率;采用半数致死量法测定8种杀虫剂对三带喙库蚊幼虫的LC50。结果乙脑高发区养殖场所三带喙库蚊平均密度为194．91只／人工小时;区分剂量法测定敌敌畏、溴氰菊酯对南郑、汉阴、汉滨、平利4个县（区）三带喙库蚊幼虫的24h死亡率分别为1．84％～13．65％和10．86％～31．25％;半数致死量法测定同一种杀虫剂对不同地区三带喙库蚊的LC50相差1．27-8．00倍。结论三带喙库蚊为陕西省乙脑高发区养殖场所的优势蚊种。除平利、南郑2个县三带喙库蚊对DDT敏感,汉滨、南郑2个县三带喙库蚊对氯氰菊酯敏感外,4个调查点的三带喙库蚊对所测试的其他杀虫剂均不同程度地产生了抗药性,其中对敌敌畏和溴氰菊酯的抗药性均达到高抗水平,对氯菊酯的抗药性达到中抗以上水平。化学防制中宜采取禁用、轮用和混用药物等措施以延缓抗药性的发展。     

云南三带喙库蚊分布特点及自然感染乙型脑炎病毒的调查

目的：研究三带喙库蚊的分布特点及乙型脑炎病毒的感染率。方法：在农村畜圈和人房捕蚊，用Ｃ６／３６细胞和小白鼠法分离病毒。结果：采获成年雌蚊３５种７０１６７只，其中三带喙库蚊２０４６４只，构成比为２９１６％，季节高峰是７～９月。从三带喙库蚊中分离出２０株乙型脑炎病毒，批阳性率为６２３％，现场感染比１∶７７２，最低带病毒率１３０‰。结论：三带喙库蚊在云南广泛分布，属优势蚊种，是云南乙型脑炎的主要传播媒介。     

湖北省黄石市三带喙库蚊密度及猪血清流行性乙型脑炎抗体水平调查

目的了解湖北省黄石市流行性乙型脑炎（乙脑）传播媒介的种类、密度及动物宿主的乙脑病毒感染状况,为制定乙脑防控措施提供科学依据。方法于2008年4-10月动态监测蚊虫种类、密度和猪血清乙脑抗体水平;蚊媒监测采用人工小时法,猪血清抗体实验室检测采用PCR。结果黄石市的优势蚊种为三带喙库蚊,其次是致倦库蚊和中华按蚊;其中三带喙库蚊占捕蚊总数的51.99%,密度为3.97只/人工小时;蚊密度最高峰出现在6月下半月,7月上半月至10月底基本恒定。猪血清乙脑抗体平均阳性率6.2%,最高村阳性率7.2%,随着时间变化呈上升趋势。结论湖北省黄石市乙脑传播媒介库蚊密度高,宿主动物猪感染率随蚊虫密度增高而变化,存在乙脑传播的自然环境。     

云南三带喙库蚊分布特点及自然感染乙型脑炎病毒 …

目的：研究三带喙库蚊的分布特点及乙型脑炎病毒的感染率。方法：在农村畜圈和人房捕蚊,用Ｃ６／３６细胞和小白鼠法分离病毒。结果：采获成年雌蚊３５种７０１６７只,其中三带喙库蚊２０４６４只,构成比为２９．１６％,季节高峰是７￣９月。从三带喙库蚊中分离出２０株乙型脑炎病毒,批阳性率为６．２３％,现场感染比１：７７２,最低带病毒率１．３０‰。结论：三带喙库蚊在云南广泛分布,属优势蚊种,是云南乙型脑炎的主要传     

实时荧光RT-PCR法快速检测三带喙库蚊中的流行性乙型脑炎病毒

目的从四川省成都地区采集三带喙库蚊样品,快速检测蚊虫中的流行性乙型脑炎病毒(JEV),并确定JEV基因型别。方法采用实时荧光RT-PCR方法检测蚊体内的JEV。利用一步法RT-PCR试剂盒扩增阳性样品Pr M区段特异性核苷酸序列,测序后应用Clustal X1.83和Mega 5.0软件构建系统进化树,并进行基因分型和同源性分析。结果 2012年采集三带喙库蚊雌蚊10 656只,分为219份,检测出7份JEV阳性核酸样品,阳性率为3.2%。扩增Pr M区域特异性核苷酸序列674 bp,经鉴定均为基因Ⅰ型。与国内外部分GⅠ型的相关序列比较,核苷酸同源性为91.5%~100%,氨基酸同源性为94.9%~100%,其中与四川省SC09-X08株同源性最高。结论实时荧光RT-PCR法能快速检测三带喙库蚊中的JEV,成都地区存在基因Ⅰ型JEV流行。     

三带喙库蚊实验室种群的建立

三带喙库蚊 (CulextritaeniorhynchusGiles 190 1)是流行性乙型脑炎和丝虫病的重要传播媒介 ,在我国分布很广 ,对人类危害甚大。关于该蚊的人工饲养 ,Newson(195 6 )和Blakeslee等在日本 4 0 6医学实验室培育成功 ,繁殖 6代。在国内 ,1973年张淑媛等〔1〕亦首次在实验室人工饲养繁殖成功。为了探索简便、能大量繁殖三带喙库蚊的饲养方法 ,我们于 1982年 8月在实验室对沈阳地区的三带喙库蚊人工饲养驯化难点进行了研究 ,经过不断的探索、改进 ,在较短的时间内获得成功 ,在东北地区首次建立了三带喙库蚊实验室种群。该方法大大地简化了饲养…     

辽宁省三带喙库蚊种群动态监测

目的掌握辽宁省三带喙库蚊的种群动态,为制定流行性乙型脑炎(乙脑)防制策略提供科学依据。方法 2006-2013年在辽宁省14个市采用诱蚊灯法开展三带喙库蚊种群数量和分布以及季节消长调查。结果辽宁省三带喙库蚊种群主要分布于丹东、大连和盘锦市,全省三带喙库蚊构成比最高的是丹东市(78.43%),其中2007年密度最高达到780.20只/(台·h),另外大连、盘锦、营口、葫芦岛和锦州市在不同年份也捕获到少量的三带喙库蚊;三带喙库蚊密度高峰集中在每年9月。结论辽宁省三带喙库蚊主要分布在沿海城市的稻田种植区,包括丹东、大连、盘锦和葫芦岛市;密度和构成比最高地区为丹东市。辽宁省为乙脑疫情高发地区,三带喙库蚊出现早、密度高,可见三带喙库蚊种群动态与乙脑发生关系密切,因此密切调查乙脑疫情和三带喙库蚊的种群动态分布不容忽视。     

三带喙库蚊在三亚和琼中的季节消长及其影响调查

目的探讨蚊媒密度、季节消长及环境因素对人间乙脑流行的影响,为开展乙脑疫情预测预警和制定防控措施提供科学依据。方法查阅资料,根据历年发病情况选择监测点,了解该地自然环境状况,采用诱蚊灯法,城区选择居民区、公园、医院,农村选择民房和牲畜棚(牛棚、猪圈)各3处,每月2次,使用诱蚊灯从日落20min后开始,连续6h,监测种类、性别并计数,密度(只/h)=捕获蚊虫数/捕蚊时间×灯数。结果两个调查点气候地理等自然环境明显不同,蚊虫种类有致倦库蚊72.9%、三带喙库蚊5.4%、白蚊伊蚊0.7%、埃及伊蚊0.3%、中华按蚊1.3%和其他蚊种19.4%,三带喙库蚊构成比三亚为11.7%,琼中为3.6%。,两个调查点三带喙库蚊平均密度三亚市0.15只/人工小时、琼中0.17只/人工小时;三亚市一年四季三带喙库蚊密度较均衡,高峰期5~9月,琼中县三带喙库蚊高峰期明显,6～7月为高峰期,其他月份密度较低,与病例分布基本一致。结论三带喙库蚊生长繁殖周期长,在蚊种中所占的比例高可能是三亚市乙脑发病数高于琼中县的主要原因,三带喙库蚊生长繁殖周期与温度、地形地貌、稻田种植面积及生猪养殖有密切关系。     

城市中三带喙库蚊新孳生地的发现

在我国三带喙库蚊是流行性乙型脑炎(乙脑)的主要传播媒介。在以往的文献报道中,三带喙库蚊主要孳生于稻田、较清的污水和静止或半流动的水体中,如具有向阳泥底、水位较低、漂浮植物丛生的池塘、沼泽、水坑、洼地、容器积水、灌溉沟渠等。随着农村和郊区的不断城市化,三带喙库蚊的孳生地也随之有了新的变化,2006年8-9月,在北京市区某小区的下水道口污水中,首次发现了三带喙库蚊幼虫的孳生。不仅如此,还发现了淡色库蚊、白纹伊蚊和三带喙库蚊同时孳生于同一个下水道口的现象。2006年8月31日,检查小区中积水下水道口19个,发现孳生三带喙库蚊幼…     

The pathogenesis of Japanese encephalitis virus in Culex tritaeniorhynchus mosquitoes

Culex tritaeniorhynchus were inoculated intrathoracically with mosquito and human strains of Japanese encephalitis virus and maintained at 26 degrees C or 32 degrees C. Virus titration and localization of viral antigen by avidin-biotin immunoperoxidase staining were done at intervals up to 21 days. Marked differences were noted in the tempo of organ involvement at the 2 temperatures; at both there was initial infection of fat body cells followed by selective infection of the central nervous system (CNS), with consistent infection of cells of the compound eye, patchy involvement of cephalic, thoracic and abdominal ganglia and no infection of Johnston's organ. CNS infection was always present 4 days after infection, when salivary gland involvement was first seen at 32 degrees C; at 26 degrees C CNS infection preceded salivary gland infection by 2 weeks. Late involvement of gut cells, pericardial cells and oviducts was also found, with no involvement of muscle.     

Ecological studies on Culex tritaeniorhynchus as a vector of Japanese encephalitis

In the Republic of Korea, light-trap assessments and collections from cows and pigs after sunset were highly successful in monitoring the seasonal abundance of C. tritaeniorhynchus, the primary vector of Japanese encephalitis. The dates and duration of the population peaks at semirural suburbs of Seoul and Pusan were markedly different from those at a rural rice-growing site. The main breeding sites in these three areas were, respectively, swamps, marshes, and ricefields. The overall adult densities were the lowest at the rice-growing site where agricultural pesticides were extensively used. A short period of man—vector contact occurred at each study site at low densities when the natural population was at its peak. These vector monitoring techniques, coupled with information on antibodies in swine, represent a simple but valuable surveillance system.     

两种多杀菌素剂型对三带喙库蚊幼虫现场防治评价

目的评估多杀菌素不同剂型Natular G30(颗粒剂)和Natular T30(片剂)在大型野外模拟水稻田小区中控制三带喙库蚊幼虫的效果。方法选择海口市美兰区灵山镇作为研究现场,利用牛帐诱法采集三带喙库蚊饱血成蚊,带回实验室蚊种复核鉴定,待其产卵孵化出幼虫后,释放于现场模拟稻田的人造小区中。实验小区(n=25)施洒Natular G30和Natular T30,对照小区(n=12)不施洒杀虫剂。定期记录实验前后各小区蚊幼及蛹的数量,计算减退率。试验前,记录实验小区内相关水质指标,如pH、温度、总固体含量、盐度、溶解氧含量等。利用SPSS17.0和Excel2007进行统计分析。结果 Natular T30处理后第1天三带喙库蚊大龄幼虫减退率为10.14%,处理后2周内三带喙库蚊大龄幼虫及蛹减退率均低于80%。Natular G30处理24 d后三带喙库蚊大龄幼虫减退率达到70.06%。结论在大型野外试验中,多杀菌素Natular G30较Natular T30对三带喙库蚊控制持效期长。     

广西流行性乙型脑炎控制策略的应用与评价

目的分析广西壮族自治区2005—2012年流行性乙型脑炎（乙脑）流行特征,评价乙脑控制策略的效果。方法采用描述流行病学方法分析乙脑流行特征,对实施国家扩大免疫规划前后的流行特征进行比较,同时对当地曾经采取的季节性突击接种、普种、应急接种、常规接种免疫及建立监测系统等控制乙脑流行策略的效果进行评价。结果 8年间发生乙脑1 135例,年平均发病率为0.29/10万;2005—2012年乙脑发病率呈逐年下降趋势,以年均16.80%速度递减。实施扩大免疫规划后发病高峰日（7月1日）延后,流行高峰期（6月2日至7月29日）延长;乙脑疫区范围逐渐缩小;5-7岁儿童发病率至2012年维持在较高水平（1.11/10万-1.79/10万）,将成为乙脑高危人群。结论通过监测系统的建立与国家扩大免疫规划策略的实施,消除了乙脑暴发与流行,打破流行周期,发病率降至历史最低水平。     

A mark-release-recapture experiment with Culex tritaeniorhynchus Giles

A mark-release-recapture experiment with the progeny of wild collected Culex tritaeniorhynchus was conducted at the village of Khokhar near Lahore, Pakistan, during June–July 1976, the onset of the monsoon. Recapture rates for each of three releases ranged from a low of 0·19% for males to a high of 0·58% for females. Male and female recaptures were well correlated with the dispersion patterns of the unmarked adults which suggested that the released adults selected similar resting habitats as the wild population. The direction of dispersal appeared random and marked, unfed females were captured biting buffaloes at the most distant collection site, 1·22 km from the release point. The initial gonotrophic cycle of the released females was completed six to eight days after emergence. The last marked female and male specimens were collected 13 and 15 days after the day of release, respectively. Released virgin females were all inseminated by the second night. The modified Lincoln index and Jackson's positive method (based on an eight-day sampling sequence) provided relatively similar estimates of population size which were considered realistic. Jackson's negative method, based on a three-day recapture chain, provided a substantial underestimate of survivorship and thus an underestimate of population size.     

邯郸市农村三带喙库蚊监测结果分析

目的掌握邯郸市三带喙库蚊的基础数据,为预防流行性乙型脑炎提供科学依据。方法诱蚊灯法。结果 2008、2009年三带喙库蚊在牲畜棚为优势种,其捕获率均达到80%以上。结论三带喙库蚊的防控应以农村牲畜棚为重点。     

流行性乙型脑炎的临床及影像学特征分析

目的 探讨山东省济宁市流行性乙型脑炎(乙脑)的临床及影像学特征。方法 收集2013年1月至2016年12月山东省济宁市第二人民医院收治的的18例乙脑临床资料,回顾性分析其临床与影像学特征。对病例资料采用描述性分析的统计学方法。结果 18例乙脑患者除均表现出高热、意识障碍、惊厥、肢体瘫痪外,其中1例还表现出帕金森综合征的症状及体征。影像学方面,流行性乙型脑炎主要累及双侧基底节区、丘脑,DWI弥散受限呈高信号,相应部位ADC图未见明显信号减低,强化后病灶未见明显强化。结论 乙脑除病毒性脑炎常见临床表现外,部分病例表现出双侧基底节、丘脑对称性受累,并且弥散受限是乙脑的特征性影像学改变。     

Prediction Forecast for Culex tritaeniorhynchus Populations in Korea

Objectives

Japanese encephalitis is considered as a secondary legal infectious disease in Korea and is transmitted by mosquitoes in the summer season. The purpose of this study was to predict the ratio of Culex tritaeniorhynchus to all the species of mosquitoes present in the study regions.

Methods

From 1999 to 2012, black light traps were installed in 10 regions in Korea (Busan, Gyeonggi, Gangwon, Chungbuk, Chungnam, Jeonbuk, Jeonnam, Gyeongbuk, Gyeongnam, and Jeju) to capture mosquitoes for identification and classification under a dissecting microscope. The number of mosquitoes captured/week was used to calculate its daily occurrence (mosquitoes/trap/night). To predict the characteristics of the mosquito population, an autoregressive model of order p (AR(p)) was used to execute the out-of-sample prediction and the in-sample estimation after presumption.

Results

Compared with the out-of-sample method, the sample-weighted regression method''s case was relatively superior for prediction, and this method predicted a decrease in the frequency of Cx. tritaeniorhynchus for 2013. However, the actual frequency of this species showed an increase in frequency. By contrast, the frequency rate of all the mosquitoes including Cx. tritaeniorhynchus gradually decreased.

Conclusion

The number of patients with Japanese encephalitis has been strongly associated with the occurrence and density of vector mosquitoes, and the importance of this infectious disease has been highlighted since 2010. The 2013 prediction indicated an increase after an initial decrease, although the ratio of the two mosquito species decreased. The increase in vector density may be due to changes in temperature and the environment. Thus, continuous prevalence prediction is warranted.