Centers for Disease Control and Prevention, Division of Parasitic Diseases and Malaria, Atlanta, GA, USA.
Malar J. 2013 Apr 30;12:143. doi: 10.1186/1475-2875-12-143.
Operational vector sampling methods lack standardization, making quantitative comparisons of malaria transmission across different settings difficult. Human landing catch (HLC) is considered the research gold standard for measuring human-mosquito contact, but is unsuitable for large-scale sampling. This study assessed mosquito catch rates of CDC light trap (CDC-LT), Ifakara tent trap (ITT), window exit trap (WET), pot resting trap (PRT), and box resting trap (BRT) relative to HLC in western Kenya to 1) identify appropriate methods for operational sampling in this region, and 2) contribute to a larger, overarching project comparing standardized evaluations of vector trapping methods across multiple countries.
Mosquitoes were collected from June to July 2009 in four districts: Rarieda, Kisumu West, Nyando, and Rachuonyo. In each district, all trapping methods were rotated 10 times through three houses in a 3 × 3 Latin Square design. Anophelines were identified by morphology and females classified as fed or non-fed. Anopheles gambiae s.l. were further identified as Anopheles gambiae s.s. or Anopheles arabiensis by PCR. Relative catch rates were estimated by negative binomial regression.
When data were pooled across all four districts, catch rates (relative to HLC indoor) for An. gambiae s.l (95.6% An. arabiensis, 4.4% An. gambiae s.s) were high for HLC outdoor (RR = 1.01), CDC-LT (RR = 1.18), and ITT (RR = 1.39); moderate for WET (RR = 0.52) and PRT outdoor (RR = 0.32); and low for all remaining types of resting traps (PRT indoor, BRT indoor, and BRT outdoor; RR < 0.08 for all). For Anopheles funestus, relative catch rates were high for ITT (RR = 1.21); moderate for HLC outdoor (RR = 0.47), CDC-LT (RR = 0.69), and WET (RR = 0.49); and low for all resting traps (RR < 0.02 for all). At finer geographic scales, however, efficacy of each trap type varied from district to district.
ITT, CDC-LT, and WET appear to be effective methods for large-scale vector sampling in western Kenya. Ultimately, choice of collection method for operational surveillance should be driven by trap efficacy and scalability, rather than fine-scale precision with respect to HLC. When compared with recent, similar trap evaluations in Tanzania and Zambia, these data suggest that traps which actively lure host-seeking females will be most useful for surveillance in the face of declining vector densities.
运营性向量采样方法缺乏标准化，使得在不同环境下对疟疾传播进行定量比较变得困难。人体降落捕捉（HLC）被认为是衡量人与蚊子接触的研究金标准，但不适合大规模采样。本研究评估了在肯尼亚西部，CDC 灯诱捕器（CDC-LT）、Ifakara 帐篷诱捕器（ITT）、窗出口诱捕器（WET）、罐式休息诱捕器（PRT）和箱式休息诱捕器（BRT）相对于 HLC 的蚊子捕获率，以 1）确定该地区适合运营性采样的方法，2）为一个更大的、涵盖多个国家的向量诱捕方法标准化评估的项目做出贡献。
2009 年 6 月至 7 月，在肯尼亚西部的四个地区（拉利埃达、基苏木西部、尼亚安多和拉乔尤尼奥）进行了蚊子采集。在每个地区，所有的诱捕方法都通过 3x3 拉丁方设计在 3 所房屋中旋转了 10 次。按形态鉴定按蚊，并将雌性分为吸血和未吸血两类。进一步通过 PCR 将冈比亚按蚊复合体鉴定为冈比亚按蚊亚种或阿拉伯按蚊。通过负二项式回归估计相对捕获率。
当将所有四个地区的数据汇总时，冈比亚按蚊复合体（95.6%的阿拉伯按蚊，4.4%的冈比亚按蚊亚种）的 HLC 户外（RR=1.01）、CDC-LT（RR=1.18）和 ITT（RR=1.39）的捕获率较高；WET（RR=0.52）和 PRT 户外（RR=0.32）的捕获率为中等；所有其他类型的休息诱捕器（PRT 室内、BRT 室内和 BRT 室外）的捕获率较低（RR<0.08）。对于致倦库蚊，ITT（RR=1.21）的相对捕获率较高；HLC 户外（RR=0.47）、CDC-LT（RR=0.69）和 WET（RR=0.49）的捕获率中等；所有休息诱捕器的捕获率较低（RR<0.02）。然而，在更细的地理尺度上，每种诱捕器类型的效果在不同地区有所不同。
ITT、CDC-LT 和 WET 似乎是肯尼亚西部大规模向量采样的有效方法。最终，操作监测中采集方法的选择应该取决于诱捕器的效果和可扩展性，而不是相对于 HLC 的精细尺度精度。与坦桑尼亚和赞比亚最近类似的诱捕器评估相比，这些数据表明，对于不断下降的媒介密度，主动吸引宿主寻求雌性的诱捕器将最有利于监测。
