Centre de Recherche Entomologique de Cotonou, Cotonou 06 BP 2604, Benin.
Parasit Vectors. 2013 Nov 4;6(1):319. doi: 10.1186/1756-3305-6-319.
A dynamic study on the transmission of malaria was conducted in two areas (R⁺ area: Low resistance area; R⁺⁺⁺ area: High resistance area) in the department of Plateau in South Eastern Benin, where the population is protected by Long Lasting Insecticidal Nets (LLINs). The aim of this study was to determine if the resistance of malaria vectors to insecticides has an impact on their behavior and on the effectiveness of LLINs in the reduction of malaria transmission.
Populations of Anopheles gambiae s.l. were sampled monthly by human landing catch in the two areas to evaluate human biting rates (HBR). Collected mosquitoes were identified morphologically and female Anopheles mosquitoes were tested for the presence of Plasmodium falciparum antigen as assessed using ELISA. The entomological inoculation rate (EIR) was also calculated (EIR = HBR x sporozoitic index [S]). We estimated the parity rate by dissecting the females of An. gambiae. Finally, window catch and spray catch were conducted in order to assess the blood feeding rate and the exophily rate of vectors.
After 6 months of tracking the mosquito's behavior in contact with the LLINs (Olyset) in R⁺⁺⁺ and R⁺ areas, the entomological indicators of the transmission of malaria (parity rate and sporozoitic index) were similar in the two areas. Also, An. gambiae populations showed the same susceptibility to P. falciparum in both R⁺ and R⁺⁺⁺ areas. The EIR and the exophily rate are higher in R⁺ area than in R⁺⁺⁺ area. But the blood-feeding rate is lower in R⁺ area comparing to R⁺⁺⁺.
The highest entomological inoculation rate observed in R⁺ area is mostly due to the strong aggressive density of An. gambiae recorded in one of the study localities. On the other hand, the highest exophily rate and the low blood-feeding rate recorded in R⁺ area compared to R⁺⁺⁺ area are not due to the resistance status of An. gambiae, but due to the differences in distribution and availability of breeding sites for Anopheles mosquitoes between areas. However, this phenomenon is not related to the resistance status, but is related to the environment instead.
在贝宁东南部高原省的两个地区（R⁺ 区：低抗区；R⁺⁺⁺ 区：高抗区）进行了一项疟疾传播的动态研究，该地区的人口受到长效驱虫蚊帐（LLINs）的保护。本研究的目的是确定疟疾媒介对杀虫剂的抗药性是否会影响它们的行为以及 LLINs 在降低疟疾传播方面的效果。
每月通过人诱捕法在两个地区采集冈比亚按蚊种群样本，以评估人群叮咬率（HBR）。收集的蚊子通过形态学鉴定，并用 ELISA 检测雌性按蚊是否存在恶性疟原虫抗原。还计算了昆虫接种率（EIR）（EIR=HBR x 孢子指数[S]）。我们通过解剖冈比亚按蚊的雌性来估计生殖率。最后，进行窗捕和喷雾捕集，以评估媒介的吸血率和外生性率。
在 R⁺⁺⁺ 和 R⁺ 地区追踪蚊子接触 LLINs（Olyset）后 6 个月，疟疾传播的昆虫学指标（生殖率和孢子指数）在两个地区相似。此外，在 R⁺ 和 R⁺⁺⁺ 地区，冈比亚按蚊种群对恶性疟原虫的敏感性相同。EIR 和外生性率在 R⁺ 地区高于 R⁺⁺⁺ 地区。但是 R⁺ 地区的吸血率比 R⁺⁺⁺ 地区低。
在 R⁺ 地区观察到的最高昆虫接种率主要是由于在一个研究地点记录到的冈比亚按蚊强烈的侵袭密度。另一方面，与 R⁺⁺⁺ 地区相比，R⁺ 地区记录到的最高外生性率和较低的吸血率并不是由于冈比亚按蚊的抗药性，而是由于两个地区间按蚊滋生地的分布和可用性的差异。然而，这种现象与抗药性无关，而是与环境有关。
