Research Institute of Yaounde (IRY), Organization de Coordination pour la lutte contre les Endémies en Afrique Centrale (OCEAC), B.P. 288, Yaoundé, Cameroon.
Department of Biological Sciences, Faculty of Medicine and Pharmaceutical Sciences, University of Douala, P.O. Box 2701, Douala, Cameroon.
Parasit Vectors. 2018 Apr 18;11(1):253. doi: 10.1186/s13071-018-2809-5.
Following the recent discovery of the role of Anopheles rufipes Gough, 1910 in human malaria transmission in the northern savannah of Cameroon, we report here additional information on its feeding and resting habits and its susceptibility to the pyrethroid insecticide deltamethrin.
From 2011 to 2015, mosquito samples were collected in 38 locations across Garoua, Mayo Oulo and Pitoa health districts in North Cameroon. Adult anophelines collected using outdoor clay pots, window exit traps and indoor spray catches were checked for feeding status, blood meal origin and Plasmodium circumsporozoite protein. The susceptibility of field-collected An. rufipes to deltamethrin was assessed using WHO standard procedures.
Of 9327 adult Anopheles collected in the 38 study sites, An. rufipes (6.5%) was overall the fifth most abundant malaria vector species following An. arabiensis (52.4%), An. funestus (s.l.) (20.8%), An. coluzzii (12.6%) and An. gambiae (6.8%). This species was found outdoors (51.2%) or entering houses (48.8%) in 35 suburban and rural locations, together with main vector species. Apart from human blood with index of 37%, An. rufipes also fed on animals including cows (52%), sheep (49%), pigs (16%), chickens (2%) and horses (1%). The overall parasite infection rate of this species was 0.4% based on the detection of P. falciparum circumsporozoite proteins in two of 517 specimens tested. Among the 21 An. rufipes populations assessed for deltamethrin susceptibility, seven populations were classified as "susceptible" (mortality ≥ 98%) , ten as "probable resistant" with a mortality range of 90-97% and four as "resistant" with a mortality range of 80-89%.
This study revealed changeable resting and feeding behaviour of An. rufipes, as well as further evidence on its ability to carry human malaria parasites in North Cameroon. Besides, this species is developing physiological resistance to deltamethrin insecticide which is used in treated nets and agriculture throughout the country, and should be regarded as one of potential targets for the control of residual malaria parasite transmission in Africa.
最近在喀麦隆北部热带稀树草原发现了 Rufipes 按蚊（Anopheles rufipes Gough, 1910）在人类疟疾传播中的作用，在此我们报告有关其取食和栖息习性以及对拟除虫菊酯杀虫剂溴氰菊酯敏感性的更多信息。
2011 年至 2015 年，在喀麦隆北部的加鲁阿、马约奥卢和皮托阿卫生区的 38 个地点采集了蚊子样本。使用户外粘土罐、窗口出口陷阱和室内喷雾采集器采集的成年按蚊检查取食状态、血液来源和环子孢子蛋白。使用世界卫生组织标准程序评估现场采集的 Rufipes 按蚊对溴氰菊酯的敏感性。
在 38 个研究地点采集的 9327 只成年按蚊中，Rufipes 按蚊（6.5%）是继阿拉伯按蚊（An. arabiensis）（52.4%）、致倦库蚊（An. funestus）（s.l.）（20.8%）、库蚊复合体（An. coluzzii）（12.6%）和冈比亚按蚊（An. gambiae）（6.8%）之后，第五种最丰富的疟疾媒介物种。该物种在 35 个郊区和农村地点的户外（51.2%）或进入房屋（48.8%）处被发现，同时还有主要的媒介物种。除了指数为 37%的人类血液外，Rufipes 按蚊还以包括牛（52%）、绵羊（49%）、猪（16%）、鸡（2%）和马（1%）在内的动物为食。在检测的 517 个标本中，有两个检测到恶性疟原虫环子孢子蛋白，该物种的寄生虫总感染率为 0.4%。在评估对溴氰菊酯敏感性的 21 个 Rufipes 种群中，有七个种群被归类为“敏感”（死亡率≥98%），十个种群被归类为“可能具有抗药性”，死亡率范围为 90-97%，四个种群被归类为“抗药性”，死亡率范围为 80-89%。
本研究揭示了 Rufipes 按蚊可变的栖息和取食行为，以及在喀麦隆北部发现其携带人类疟原虫的进一步证据。此外，该物种对溴氰菊酯杀虫剂产生了生理抗性，这种杀虫剂在全国范围内用于处理过的蚊帐和农业，应被视为控制非洲残留疟原虫传播的潜在目标之一。
