Abstract: Objective To investigate mosquito species and Plasmodium sporozoite infection in Anopheles mosquitoes in Laiza city, Myanmar, and provide a basis for local malaria control and prevention.Methods Four residential sites were selected in Laiza city (within 2 km from the border), and five human houses were selected at each site for capturing mosquitoes. Mosquitoes were collected with a light trap each inside and outside every house overnight for three days, twice per month from July to September, 2018. Mosquito species were determined by morphological identification. The positive rate of Plasmodium sporozoite infection in Anopheles mosquitoes was examined by using nested PCR, with five Anopheles mosquitoes per group.Results A total of 2 041 mosquitoes of four genera were collected, including 815 (39.93%) Culex mosquitoes, 16 (0.78%) Aedes mosquitoes, 453 (22.20%) Armigeres mosquitoes, and 757 (37.09%) Anopheles mosquitoes. There were 10 Anopheles species, in which An. minimus was the local dominant species, accounting for 85.87% (650/757), followed by An. culicifacies (5.02%). A total of 667 An. minimus mosquitoes in 135 groups were examined by PCR. Among them, 11 groups were positive for the target fragment of P. vivax, all labeled as An. minimus, with a detection rate of 8.15%. In the positive 11 groups, at least one An. minimus mosquito in each group carried P. vivax sporozoites, and the minimum Plasmodium sporozoite infection rate in An. minimus mosquitoes was 1.69% (11/650). The minimum infection rates of Zhatugong and Chunmuweng sites were 1.74% and 1.89%, respectively, without statistical difference (χ²=0.012, P=0.912). The infection rate was zero at Jiyangka and Penlongyang sites.Conclusions An. minimus was the dominant Anopheles species in Laiza city, Myanmar, which was the main vector for local malaria transmission, with a high rate of Plasmodium sporozoite infection.

Key words: Myanmar, Laiza city, Mosquito, Anopheles, Plasmodium sporozoite, Nested PCR

摘要： 目的 了解缅甸拉咱市蚊虫种类和按蚊疟原虫子孢子感染情况,为当地疟疾防治提供依据。方法 2018年7－9月在缅甸拉咱市选择边境县2 km内的4个居民点为调查点,每个调查点选择5间人房作为捕蚊点,每月2次每次3 d在室内外各悬挂1台诱蚊灯通宵诱蚊,捕获的蚊虫进行形态学鉴定。鉴定后的按蚊按5只/组,采用巢式聚合酶链式反应（PCR）检测按蚊疟原虫子孢子阳性率。结果 共捕获蚊虫4属2 041只,其中库蚊属占39.93%（815/2 041）,伊蚊属占0.78%（16/2 041）,阿蚊属占22.20%（453/2 041）,按蚊属占37.09%（757/2 041）。共捕获按蚊10种,其中微小按蚊650只,占捕获按蚊总数的85.87%,为当地优势蚊种；其次为库态按蚊,占5.02%。PCR检测135组667只蚊虫,共有11组样品扩增出间日疟原虫目标片段,均标记为微小按蚊,检出率为8.15%。检测出的11组中,每组至少有1只微小按蚊携带间日疟原虫子孢子,推算微小按蚊疟原虫子孢子最低感染率为1.69%（11/650）,其中扎突拱和纯木翁调查点最低感染率分别为1.74%和1.89%,但二者差异无统计学意义（χ²=0.012,P=0.912）；吉阳卡和盆龙样调查点疟原虫子孢子感染率均为0。结论 微小按蚊是缅甸拉咱市优势按蚊,是当地主要传疟媒介,且疟原虫子孢子感染率较高。

关键词: 缅甸, 拉咱市, 蚊虫, 按蚊, 疟原虫子孢子, 巢式聚合酶链式反应