西藏林芝地区墨脱县传疟媒介调查研究

目的 调查西藏林芝地区墨脱县传疟媒介,为制定针对性防制措施提供依据。 方法 2007年7～8月在墨脱县选择3个疟疾发病率较高的自然村,采用通宵/半通宵室内、外人/牛饵帐诱捕法、通宵人/牛房诱蚊灯诱捕法和清晨人房搜捕法捕蚊,对捕获的按蚊进行形态学鉴定,并进行种群组成、密度、叮人率、吸血习性、栖息习性和经产蚊比率等观察;在不同的水体捞取按蚊幼虫,进行蚊种鉴定,调查按蚊幼虫孳生环境。 结果 共捕获按蚊5 345只,经形态鉴定,只发现伪威氏按蚊、威氏按蚊和带足按蚊等3种,其中伪威氏按蚊占94.71%（5 062/5 345）,威氏按蚊与带足按蚊分别为2.39%（128/5 345）和2.90%（155/5 345）。伪威氏按蚊室内和室外的半通宵诱捕平均密度分别为17只/人和105只/人;全通宵室内和室外的人饵帐诱平均叮人率分别为15.80只/（人·夜）（79/5）和326.22只/（人·夜）（1 468/4.5）;全通宵室外人、牛饵诱捕及人、牛房诱蚊灯灯诱,伪威氏按蚊趋吸人血与牛血的比率分别为30.51%（714/2 340）和69.49%（1 626/2 340）及32.02%（57/178）和67.98%（121/178）,表明伪威氏按蚊偏吸牛血并兼吸人血;清晨人房搜捕,共捕获伪威氏按蚊7只,均为胃血未消化的饱血蚊;共捞获按蚊幼虫106条,其中伪威氏按蚊和威氏按蚊幼虫62条,带足按蚊幼虫44条,按蚊幼虫孳生的水体类型仅限于稻田。 结论 伪威氏按蚊具备在当地传播疟疾的媒介生物学条件。     

西藏墨脱县疟疾暴发自然村伪威氏按蚊与威氏按蚊生态习性比较

目的 目的 调查西藏疟疾流行区墨脱县中、 高海拔地区主要按蚊伪威氏按蚊和威氏按蚊的生态习性及其传播疟疾的 潜能。 方法 方法 采用人诱、 动物诱 （牛、 马、 猪） 和诱蚊灯诱捕方法捕获成蚊, 分析按蚊密度、 夜间活动规律、 室内外吸血习性; 对于捕获的经形态学鉴定为多斑按蚊复合体的蚊虫, 按照捕蚊时间、 地点和捕蚊方式进行标记, 带回实验室后采用PCR方 法鉴定蚊种; 采用晨捕和白天搜捕法判断按蚊栖息习性; 在不同类型水体捕捞幼虫, 饲养羽化以判定孳生地。 结果 结果 共捕 获多斑按蚊复合体蚊虫1 053只, 其中伪威氏按蚊331只, 威氏按蚊722只。室内与室外威氏按蚊的数量均高于伪威氏按 蚊 （P < 0.01, P < 0.05）。室内外两种按蚊构成比差异无统计学意义 （P > 0.05）。伪威氏按蚊和威氏按蚊经产蚊比例分别为 65.90%和69.86%, 差异无统计学意义 （P > 0.05）, 伪威氏按蚊室外吸血蚊数大于室内吸血蚊数 （P < 0.05）, 威氏按蚊室内外 吸血蚊数差异无统计学意义 （P > 0.05）。两种按蚊夜间活动均为单峰分布, 威氏按蚊密度日落后21： 00-22： 00达高峰, 随 后逐步下降, 凌晨4： 00后未捕获威氏按蚊; 伪威氏按蚊密度高峰为24： 00至凌晨1： 00, 几乎整夜都有活动。结论 结论 西藏墨 脱县中、 高海拔地区威氏按蚊构成与密度均高于伪威氏按蚊, 两种按蚊生态习性有差异; 威氏按蚊比伪威氏按蚊更具传播 疟疾的潜能。     

西藏墨脱县疟疾流行区多斑按蚊复合体种型鉴定

目的 鉴定西藏林芝地区墨脱县疟疾流行区多斑按蚊复合体的种型。 方法 墨脱县捕获的5 190只按蚊经形态学鉴定为多斑按蚊复合体后,随机取575只,酚-氯仿法提取单蚊DNA作为模板,根据伪威氏按蚊、多斑按蚊、威氏按蚊、达罗毗按蚊和塞沃按蚊分别设计5对特异性引物,PCR扩增rDNA第二转录间隔区（ITS2）片段,进行种型鉴别。对目标片段进行测序、同源性比对,并运用MEGA（3.1）软件构建多斑按蚊复合体的系统进化树。 结果 575份DNA样本中有11份扩增出约231 bp的条带,即威氏按蚊（1.9%）;564份扩增出约119 bp的条带,为伪威氏按蚊（98.1%）。 PCR种型鉴定结果与同源性比对及系统进化树的结果一致。 结论 西藏林芝地区墨脱县疟疾流行区多斑按蚊复合体由伪威氏按蚊和威氏按蚊构成,伪威氏按蚊为优势蚊种。     

西藏林芝地区察隅县按蚊种群调查

目的确定西藏林芝地区察隅县主要按蚊蚊种。方法2010年7-8月在察隅县选择4个自然村,采用通宵/半通宵室内、外人饵帐诱捕法和通宵诱蚊灯诱捕法捕蚊,对捕获的按蚊进行形态学鉴定。结果共捕获按蚊2 991只,其中带足按蚊2 284只(占76.36%),多斑按蚊种团667只(占22.30%),其他按蚊40只(占1.34%);带足按蚊室内、外半通宵平均密度分别为56.2只/夜和4只/夜,多斑按蚊种团室内、外半通宵平均密度分别为17.8只/夜和17.9只/夜;带足按蚊室内、外全通宵室内叮人率分别为28.1只/(人夜)和2只/(人夜),多斑按蚊种团全通宵室内、外叮人率均为8.9只/(人夜)。结论带足按蚊和多斑按蚊为察隅县优势蚊种,是可能的疟疾传播媒介。     

西藏林芝地区察隅县伪威氏按蚊溴氰菊酯抗性初步调查

目的 了解西藏林芝地区察隅县按蚊优势种伪威氏按蚊对溴氰菊酯的敏感性.方法 选择察隅县下察隅镇的日玛村和塔玛村为调查点,于2011年7月采用牛诱法捕获饱血伪威氏按蚊,带回实验室繁殖至子一代,采用世界卫生组织( WHO)推荐的成蚊接触筒法对溴氰菊酯杀虫剂的敏感性进行测试,同时设立空白对照组,空白对照组和实验组测试试纸均以丙酮为溶剂,实验组为0.05％溴氰菊酯,对照组未添加杀虫剂.将待测蚊虫移入装有0.05％溴氰菊酯药膜滤纸的实验组接触筒和空白对照接触筒中,蚊虫接触供试杀虫剂60 min,计算半数击倒时间(KT50),24h后记录蚊虫死亡数,计算死亡率.结果 察隅县下察隅镇伪威氏按蚊经0.05％溴氰菊酯测试后,击倒率分别为96.4％和97.5％,校正死亡率均为100％.结论 察隅县下察隅镇伪威氏按蚊对溴氰菊酯杀虫剂敏感,可以采用溴氰菊酯对该地伪威氏按蚊进行媒介控制.     

西藏墨脱县不同海拔地区按蚊构成调查

目的探讨西藏墨脱县不同海拔自然村按蚊种类和构成。方法 2010年7月14日～8月17日,选择4种不同高度海拔的6个自然村作为调查点,在高海拔的甘德乡甘德村(海拔1966m),中高海拔的达木乡达木村(海拔1408m)与珠村(海拔1510m),中海拔的墨脱镇墨脱村(海拔1178m),低海拔的背崩乡地东村(海拔853 m)和背崩村(海拔831m),采用人诱、牛诱和灯诱等方法捕获成蚊,成蚊经形态学鉴定后处死,干燥保存带回实验室,多斑按蚊复合体采用多重PCR方法进行具体种型鉴定。结果共捕获按蚊5410只,其中高海拔区捕获按蚊2只,1只为大型按蚊贝氏亚种,另1只形态损伤无法鉴别,但形态学上可排除多斑按蚊复合体;中高海拔区捕获伪威氏按蚊541只(36.9%),威氏按蚊906只(61.7%),带足按蚊21只(1.4%);中海拔区捕获伪威氏按蚊260只(76.3%),威氏按蚊2只(0.6%),带足按蚊79只(23.2%);低海拔区捕获伪威氏按蚊3265只(90.7%),威氏按蚊19只(0.5%),带足按蚊315(8.8%)。中高、中和低海拔区通宵灯诱蚊虫密度分别为,伪威氏按蚊25.7、28.3和62.8只/夜,威氏按蚊41.5...     

应用多重PCR法鉴定蚊胃血血源的研揪

目的建立多重PCR法鉴定蚊胃血来源。方法依据常见蚊吸血对象(人、牛、猪和犬)的线粒体DNA细胞色素b序列的差异,设计种特异引物,建立多重PCR法,并应用该法检测现场按蚊标本。结果应用多重PCR法共检测249只按蚊,血源来自牛和猪的共91只和63只,未检出吸人血按蚊。立即处死并干燥保存的现场按蚊标本检测成功率最高,为92.50%。结论多重PCR法鉴定蚊胃血血源快速、灵敏,结果客观、可靠。     

应用多重PCR法鉴定蚊胃血血源的研究

目的建立多重PCR法鉴定蚊胃血来源。方法依据常见蚊吸血对象（人、牛、猪和犬）的线粒体DNA细胞色素b序列的差异,设计种特异引物,建立多重PCR法,并应用该法检测现场按蚊标本。结果应用多重PCR法共检测249只按蚊,血源来自牛和猪的共91只和63只,未检出吸人血按蚊。立即处死并干燥保存的现场按蚊标本检测成功率最高,为92.50%。结论多重PCR法鉴定蚊胃血血源快速、灵敏,结果客观、可靠。     

云南省边境地区景洪市疟疾媒介调查

目的了解云南省边境地区景洪市疟疾重要传播媒介的按蚊种类、生态习性及其疟原虫子孢子感染情况。方法于2015年在景洪市选取1个历史上疟疾流行高发村曼辉龙村为调查点,6-10月每月捕蚊3 d。在调查点东、西、南、北、中5个方位各选择1户人房和畜房,采用灯诱法通宵捕捉按蚊,调查按蚊种群密度;多重PCR检测按蚊胃血,观察其嗜血习性。选择村内和村外各1处采用帐诱法捕捉按蚊,观察按蚊夜间活动规律;采用巢式PCR检测按蚊疟原虫子孢子感染情况。结果共捕获1 286只按蚊,属13种,其中中华按蚊936只(占72.8%),微小按蚊188只(占14.6%),为当地按蚊优势蚊种。按蚊的捕获来源地主要为畜房,占85.6%(1 101只)。125份中华按蚊胃血多重PCR检测结果显示,人血指数为0,猪血指数为100。中华按蚊村内叮人率为0.6只/(人·h),村外的叮人率为0.2只/(人·h),夜间活动高峰期为20∶00-22∶00。101只微小按蚊、 517只中华按蚊和40只多斑按蚊巢式PCR检测,均未发现疟原虫子孢子感染。结论景洪市按蚊媒介种群以中华按蚊为主,其次为微小按蚊。中华按蚊以嗜家畜血为主。捕获的按蚊中未检测到疟原虫子孢子感染。     

武穴市中华按蚁吸血习性三种方法调查结果比较

用三种方法调查了武穴市中华按蚊吸血习性。全村人房和各种牲畜房早晨全面搜捕采集蚊胃血标本，计算人血指数为０．０４８；夜间不同宿主直接诱捕，趋吸人血比例为１２．４３％；室外栖息场所搜捕，仅捕到少量吸血按蚊。结果分析表明，采用全村室内全面搜捕方法调查中华按蚊的人血指数，较为适合。     

Molecular identification and phylogeny of the Maculatus group of Anopheles mosquitoes (Diptera: Culicidae) based on nuclear and mitochondrial DNA sequences

The Maculatus group of Anopheles mosquitoes (Diptera: Culicidae) comprises eight known species, including important malaria vectors in Southeast Asia. The sequences of the second internal transcribed spacer (ITS2) and third domain (D3) of ribosomal DNA, and cytochrome oxidase subunit II (COII) of mitochondrial DNA were obtained for five species of the group from China, as An. maculatus, An. willmori, An. pseudowillmori, An. sawadwongporni and An. dravidicus. The variation within taxon is much smaller than that between taxa. A diagnostic PCR assay for distinguishing the five members was developed based on the interspecific ITS2 variation. The phylogenetic relationships for the group were estimated on the ITS2 and D3 data. The Maculatus group appears monophyletic with An. pseudowillmori at a basal position, the Sawadwongporni subgroup and the Maculatus subgroup form sister clades. Our data concludes that An. dispar and An. greeni belong to the Maculatus subgroup, and An. willmori is not closer to either of the subgroups.     

Population dynamics of adult mosquitoes (Diptera: Culicidae) in malaria endemic villages of Kuala Lipis, Pahang, Malaysia

Mosquitoes in malaria endemic areas needs to be monitored constantly in order to detect demographic changes that could affect control measures. A 12-month mosquito population survey was conducted in several malaria endemic areas in Pos Lenjang, Kuala Lipis, Pahang, Malaysia. Collection of mosquitoes using a human landing catch technique was carried out indoors and outdoors for 12 hours from 7:00 PM to 7:00 AM for 42 nights. Anopheles maculatus Theobald (31.0%), Armigeres flavus Leicester (11.3%), Armigeres annulitarsis Leicester (11.0%), Culex vishnui Theobald (9.6%) and Aedes albopictus Skuse (7.0%) were the predominant species caught in the study area. The salivary gland and midgut of all anopheline mosquitoes were dissected to determine the presence of malaria parasites but none were positive. A high rate of human biting by An. maculatus was detected during December, but the rate was lower in January. Mosquito larvae were carried by the rapid current of the river downstream causing a decrease in the larvae population. Of the five predominant species, only Ar. annulitarsis exhibited a significant positive correlation in numbers with monthly rainfall (p < 0.05). An. maculatus biting activity peaked during 10:00 PM to 11:00 PM. Ae. albopictus, Ar. annulitarsis, and Ar. flavus exhibited similar activities which peaked during 7:00 PM to 8.00 PM.     

The incidence of mosquitoes feeding on mothers and babies at Kisumu, Kenya.

Blood fed mosquitoes were collected inside four bed nets in which mother/child pairs, having different haptoglobin types, slept. The bloodmeals were analysed by gradient gel electrophoresis to determine on which person the mosquitoes had fed. The results suggest that the mothers are fed on much more than babies by both Anopheles gambiae s.l. and Culex fatigans. In one hut at least 15.2 per cent of the mosquitoes had taken all or part of their bloodmeal elsewhere. A greater number of double feeds were detected from engorged Cx. fatigans (12.6%) than An. gambiae s.l. (2.7%).     

Estimation of the Human Blood Index in malaria mosquito vectors in Equatorial Guinea after indoor antivector interventions

We determined the Human Blood Index (HBI) of malaria mosquito vectors in Equatorial Guinea. We used a polymerase chain reaction (PCR)-based methodology to identify blood meal sources in engorged mosquitoes. We observed high HBI values, indicating that these vectors are highly anthropophilic despite intensive intradomicillary application of residual insecticides. Our results suggest that estimating the HBI can be a relatively simple and easy way to evaluate the efficacy of antimalaria interventions where an observed diversion to non-human hosts may successfully contribute to the interruption of malaria transmission.     

我国多斑按蚊复合体成员种的分子鉴别研究

目的建立我国多斑按蚊复合体5成员种的分子鉴别方法。方法测定并分析各成员种的rDNA-ITS2序列,并设计种特异引物,应用PCR法鉴别。结果多斑按蚊复合体5成员种的ITS2序列长度和GC含量分别为伪威氏按蚊328bp、58.54％、多斑按蚊330bp、57.85％、威氏按蚊337bp、59.05％、达罗毗按蚊334bp、58.68％和塞沃按蚊338bp、57.69％,各种内的ITS2序列保守,而种间的差异率范围为9.7％～18.9％。应用5.8S引物和5个种特异引物可以分别扩增出119、186、231、327和406bp等5条清晰不同的种特异条带,以鉴别各蚊种。结论基于ITS2序列差异建立的我国多斑按蚊复合体5成员种的PCR鉴别简便易行、可靠。     

Malaria vectors in a traditional dry zone village in Sri Lanka.

Malaria transmission by anopheline mosquitoes was studied in a traditional tank-irrigation-based rice-producing village in the malaria-endemic low country dry zone of northcentral Sri Lanka during the period August 1994-February 1997. Adult mosquitoes were collected from human and bovid bait catches, bovid-baited trap huts, indoor catches, and pit traps. Mosquito head-thoraces were tested for the presence of Plasmodium falciparum and P. vivax, and blood-engorged abdomens for the presence of human blood by ELISAs. House surveys were done at two-day intervals to record cases of blood film-confirmed malaria among the villagers. A total of 7,823 female anophelines representing 14 species were collected. Trends in anopheline abundance were significantly correlated with rainfall of the preceding month in An. annularis, An. barbirostris, An. subpictus, An. vagus, and An. varuna, but were not significant in An. culicifacies and An. peditaeniatus. Malaria parasite infections were seen in seven mosquito species, with 75% of the positive mosquitoes containing P. falciparum and 25% P. vivax. Polymorph PV247 was recorded from a vector (i.e., An. varuna) for the first time in Sri Lanka. Computations of mean number of infective vector (MIV) rates using abundance, circumsporozoite (CS) protein rate, and human blood index (HBI) showed the highest rate in An. culicifacies. A malaria outbreak occurred from October 1994 to January 1995 in which 45.5% of village residents experienced at least a single disease episode. Thereafter, malaria incidence remained low. Anopheles culicifacies abundance lagged by one month correlated positively with monthly malaria incidence during the outbreak period, and although this species ranked fifth in terms of abundance, infection was associated with a high MIV rate due to a high CS protein rate and HBI. Abundance trends in other species did not correlate significantly with malaria. It was concluded that An. culicifacies was epidemiologically the most important vector in the study area.     

Anopheles (Cellia) maculatus group: Its spatial distribution and molecular characterization of member species in north-east India

Anopheles (Cellia) maculatus is considered a group of at least nine formally named species. Faced with the difficulty of correct morphological identification due to overlapping characters, several member species of the An. maculatus group are known to play important role in malaria transmission in the Oriental region. Current assemblage, distribution and vectorial importance of the member species within the Maculatus group is far from clear in the north-eastern region of India. Our study encompassing 410 individuals, collected from 67 geo-referenced spots across the eight north-east Indian states, identified the presence of 6 member species of the Maculatus group using the molecular tools. Anopheles dravidicus and Anopheles rampae were documented for the first time in this part of India with latter forming the new country record. While Anopheles pseudowillmori (59.5%) and An. maculatus (32%) were widely available species in most of the north-eastern states, restricted distribution of Anopheles willmori to Nagaland and that of Anopheles sawadwongporni and An. rampae to Mizoram state was noted. None of the species was found positive for human malaria parasite. While no intraspecific differences existed in the sequences of second internal transcribed spacer (ITS2) region of ribosomal DNA (r-DNA) of the member species of the Maculatus group within north-east India, few differences were detected in the sequences of An. dravidicus, An. maculatus and An. pseudowillmori from north-east India with species from the neighbouring countries.