National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention, Shanghai, 200025, China.
Key Laboratory of Parasite and Vector Biology, Ministry of Health, Shanghai, 200025, China.
Parasit Vectors. 2018 Sep 15;11(1):511. doi: 10.1186/s13071-018-3073-4.
Tengchong County was one of the counties located at the China-Myanmar border with high malaria incidence in the previous decades. As the pilot county for malaria elimination at the border area, Tengchong County is aiming to be the first county to achieve malaria elimination goal. A cross-sectional entomological survey was carried out to evaluate the feasibility of elimination approach and assess the receptivity of malaria reintroduction.
Light traps associated with live baits were used to investigate the abundance of adult mosquitoes in nine villages in Tengchong County. Light traps were set to collect adult mosquitoes in both human houses and cowsheds from dusk till dawn in each site.
A total of 4948 adult Anopheles mosquitoes were collected from May to December in two villages. Of the mosquitoes were captured, 24.2% were in human houses and 75.8% in cowsheds. The peak of abundance occurred in July for An. sinensis and in September-October for An. minimus (s.l.) Ten Anopheles species were collected, the most prevalent being An. sinensis (50.3%), An. peditaeniatus (31.6%) and An. minimus (s.l.) (15.8%), contributing to 97.6% of the sample. Potential breeding sites were also investigated and a total of 407 larvae were collected, with An. sinensis (50.1%) and An. minimus (s.l.) (46.2%) as predominant species. Ponds and rice fields were the two preferred breeding sites for Anopheles mosquitoes; however, the difference between the number of adults and larvae captured suggest other breeding sites might exist. Both An. sinensis and An. minimus (s.l.) were found zoophilic with human blood index as 0.21 and 0.26, respectively. No Plasmodium positive Anopheles specimens were found by PCR among 4,000 trapped mosquitoes.
Although no indigenous malaria cases have been reported in Tengchong County since 2013, there is still a risk from the presence of vectors in the context of human population movements from neighboring malaria endemic areas. The presence of An. sinensis, associated to rice fields, is particularly worrying. Sustained entomological surveillance is strongly suggested even after malaria elimination certification.
腾冲县曾是中国与缅甸接壤的疟疾高发县之一。作为边境地区消除疟疾的试点县，腾冲县的目标是成为第一个实现消除疟疾目标的县。本研究进行了一项横断面昆虫学调查，以评估消除方法的可行性并评估疟疾再次传入的接受性。
采用带活诱饵的诱蚊灯在腾冲县 9 个村庄调查成蚊密度。在每个地点，从黄昏到黎明，在人房和牛棚内设置诱蚊灯收集成蚊。
2018 年 5 月至 12 月，在两个村庄共捕获 4948 只成蚊。捕获的蚊子中，24.2%在人房，75.8%在牛棚。中华按蚊的高峰出现在 7 月，微小按蚊（s.l.）的高峰出现在 9 月至 10 月。共采集到 10 种按蚊，最常见的是中华按蚊（50.3%）、淡色库蚊（31.6%）和微小按蚊（s.l.）（15.8%），占样本的 97.6%。还调查了潜在的滋生地，共采集到 407 只幼虫，中华按蚊（50.1%）和微小按蚊（s.l.）（46.2%）是主要种类。池塘和稻田是按蚊最喜好的滋生地，但捕获的成虫和幼虫数量之间的差异表明可能存在其他滋生地。中华按蚊和微小按蚊（s.l.）均为嗜人血蚊种，人血指数分别为 0.21 和 0.26。在 4000 只捕获的蚊子中，通过 PCR 未发现疟原虫阳性的按蚊标本。
尽管自 2013 年以来腾冲县未报告本地疟疾病例，但在来自疟疾流行地区的人口流动背景下，仍存在媒介存在的风险。稻田中存在中华按蚊尤其令人担忧。建议即使在消除疟疾认证后，仍要持续进行昆虫学监测。
