Kenea Oljira, Balkew Meshesha, Tekie Habte, Gebre-Michael Teshome, Deressa Wakgari, Loha Eskindir, Lindtjørn Bernt, Overgaard Hans J
Department of Zoological Sciences, Addis Ababa University, P. O. Box 1176, Addis Ababa, Ethiopia.
Department of Biology, Wollega University, P. O. Box 395, Nekemte, Ethiopia.
Malar J. 2017 Jan 13;16(1):30. doi: 10.1186/s12936-016-1668-9.
The human landing catch (HLC) is the standard reference method for measuring human exposure to mosquito bites. However, HLC is labour-intensive, exposes collectors to infectious mosquito bites and is subjected to collector bias. These necessitate local calibration and application of alternative methods. This study was undertaken to determine the relative sampling efficiency (RSE) of light traps with or without yeast-produced carbon dioxide bait vs. HLC in south-central Ethiopia.
The experiment was conducted for 39 nights in a 3 × 3 Latin square randomized design with Anopheles arabiensis as the target species in the period between July and November 2014 in Edo Kontola village, south-central Ethiopia. Center for Disease Control and Prevention light trap catches (LTC) and yeast-generated carbon dioxide-baited light trap catches (CB-LTC) were each evaluated against HLC. The total nightly mosquito catches for each Anopheles species in either method was compared with HLC by Pearson correlation and simple linear regression analysis on log-transformed [log(x + 1)] values. To test if the RSE of each alternative method was affected by mosquito density, the ratio of the number of mosquitoes in each method to the number of mosquitoes in HLC was plotted against the average mosquito abundance.
Overall, 7606 Anopheles females were collected by the three sampling methods. Among these 5228 (68.7%) were Anopheles ziemanni, 1153 (15.2%) An. arabiensis, 883 (11.6%) Anopheles funestus s.l., and 342 (4.5%) Anopheles pharoensis. HLC yielded 3392 (44.6%), CB-LTC 2150 (28.3%), and LTC 2064 (27.1%) Anopheles females. The RSEs of LTC and HLC for An. arabiensis were significantly correlated (p < 0.001) and density independent (p = 0.65). However, for outdoor collection of the same species, RSEs of LTC and CB-LTC were density dependent (p < 0.001). It was estimated that on average, indoor LTC and CB-LTC each caught 0.35 and 0.44 times that of indoor HLC for An. arabiensis respectively.
Results showed that HLC was the most efficient method for sampling An. arabiensis. LTC can be used for large-scale indoor An. arabiensis surveillance and monitoring when it is difficult to use HLC. CB-LTC does not substantially improve sampling of this major vector compared to LTC in this setting. Trial registration PACTR201411000882128 (retrospectively registered 8 September, 2014).
人饵诱捕法（HLC）是衡量人类被蚊虫叮咬暴露情况的标准参考方法。然而，HLC劳动强度大，使采集者暴露于感染性蚊虫叮咬之下，且存在采集者偏差。因此需要进行本地校准并应用替代方法。本研究旨在确定在埃塞俄比亚中南部，带或不带酵母产生的二氧化碳诱饵的诱蚊灯与HLC相比的相对采样效率（RSE）。
2014年7月至11月期间，在埃塞俄比亚中南部的埃多孔托拉村，以阿拉伯按蚊为目标物种，采用3×3拉丁方随机设计进行了39个夜晚的实验。将疾病控制和预防中心诱蚊灯捕获量（LTC）和酵母产生的二氧化碳诱饵诱蚊灯捕获量（CB-LTC）分别与HLC进行评估。通过Pearson相关性分析和对对数转换[log(x + 1)]值的简单线性回归分析，比较每种方法中每种按蚊物种的夜间总蚊虫捕获量与HLC。为了测试每种替代方法的RSE是否受蚊虫密度影响，将每种方法中的蚊虫数量与HLC中的蚊虫数量之比与平均蚊虫丰度作图。
总体而言，三种采样方法共捕获7606只雌性按蚊。其中，5228只（68.7%）为齐氏按蚊，1153只（15.2%）为阿拉伯按蚊，883只（11.6%）为嗜人按蚊复合组，342只（4.5%）为法老按蚊。HLC捕获3392只（44.6%）雌性按蚊，CB-LTC捕获2150只（28.3%），LTC捕获2064只（27.1%）。阿拉伯按蚊的LTC和HLC的RSE显著相关（p < 0.）且与密度无关（p = 0.65）。然而，对于同一物种的室外采集，LTC和CB-LTC的RSE与密度有关（p < 0.001）。据估计，平均而言，室内LTC和CB-LTC捕获阿拉伯按蚊的数量分别是室内HLC的0.35倍和0.44倍。
结果表明，HLC是采样阿拉伯按蚊最有效的方法。当难以使用HLC时，LTC可用于大规模室内阿拉伯按蚊监测。在此环境中，与LTC相比，CB-LTC并未显著改善对这种主要病媒的采样。试验注册号：PACTR201411000882128（2014年9月8日追溯注册）。
