Anopheles parensis contributes to residual malaria transmission in South Africa
Anopheles parensis contributes to residual malaria transmission in South Africa
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DOI：
10.1186/s12936-019-2889-5
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发表时间：
2019-07-29
期刊：
影响因子：
3
通讯作者：
Brooke, Basil
中科院分区：
文献类型：
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作者：
Burke, Ashley;Dahan-Moss, Yael;Brooke, Basil
背景了解户外栖息的按蚊对残留疟疾传播的贡献对于扩大病媒控制以在南非消除疟疾具有重要意义。该项目的目的是利用夸祖鲁-纳塔尔省北部uMhanyakude区的哨点监测点，评估帕氏按蚊和其他按蚊物种在残留疟疾传播中的潜在作用。使用室外放置的陶罐诱捕器捕捉雄性和雌性成年按蚊。采集的冈比亚按蚊复合体和福氏按蚊群标本均经种鉴定，并用酶联免疫吸附试验(EL ISA)对所有雌蚊进行了恶性疟原虫环子孢子蛋白(CSP)筛查。用套式聚合酶链式反应和DNA序列分析进一步验证了恶性疟原虫的感染性。Parsis(n=194)种类最丰富。采集到的其他种类包括按蚊(n=11)、四环按蚊(n=10)、利氏按蚊(n=29)、里氏按蚊(n=18)和凡氏按蚊(n=1)。在317例筛查恶性疟原虫CSP的雌性标本中，1例为阿拉伯按蚊，1例为按蚊。经酶联免疫吸附试验和恶性疟原虫套式聚合酶链式反应均呈阳性。对于安来说。结论帕氏按蚊是南非疟疾的潜在传播媒介，但由于其强烈的嗜食动物倾向，其对疟疾传播的贡献可能最多也是最小的。相比之下，An.阿拉伯疟原虫是一种主要媒介，它是南非疟疾残留传播的主要原因。由于最近收集到的所有子孢子阳性按蚊都是在室外放置的栖息陷阱中发现的，因此有必要采取干预措施，在保持南非室内室内喷洒行动效果的同时，控制室外栖息的媒介种群。
BackgroundUnderstanding the contribution of outdoor-resting Anopheles mosquitoes to residual malaria transmission is important in terms of scaling up vector control towards malaria elimination in South Africa. The aim of this project was to assess the potential role of Anopheles parensis and other Anopheles species in residual malaria transmission, using sentinel surveillance sites in the uMkhanyakude District of northern KwaZulu-Natal Province.MethodsMonthly vector surveillance was conducted at the sentinel sites from January 2017 to May 2018. Outdoor-placed clay pot resting traps were used to collect male and female adult Anopheles mosquitoes. All Anopheles gambiae complex and Anopheles funestus group specimens collected were identified to species and all females were screened for Plasmodium falciparum circumsporozoite protein (CSP) by enzyme-linked immunosorbent assay (ELISA). Samples showing infectivity for P. falciparum were further verified by a nested PCR and subsequent DNA sequence analysis.ResultsFrom a sample of 491 anophelines, Anopheles arabiensis (n=228) and An. parensis (n=194) were the most abundant. Other species collected included Anopheles merus (n=11), Anopheles quadriannulatus (n=10), Anopheles leesoni (n=29), Anopheles rivulorum (n=18), and Anopheles vaneedeni (n=1). Of the 317 female specimens screened for P. falciparum CSP, one Anopheles arabiensis and one An. parensis showed positive by ELISA and Plasmodium nested PCR. For the An. parensis specimen, confirmation of its species identity was based on sequence analysis of the ITS2 region, and the presence of P. falciparum DNA was further confirmed by sequence analysis.ConclusionsAnopheles parensis is a potential vector of malaria in South Africa although its contribution to transmission is likely to be minimal at best owing to its strong zoophilic tendency. By contrast, An. arabiensis is a major vector that is primarily responsible for the bulk of residual malaria transmission in South Africa. As all recently collected sporozoite-positive Anopheles mosquitoes were found in outdoor-placed resting traps, it is necessary to introduce interventions that can be used to control outdoor-resting vector populations while maintaining the efficacy of South Africa's indoor house spraying operations.