Centre for Global Health Research, Kenya Medical Research Institute, P O Box 1578, Kisumu 40100, Kenya.
Parasit Vectors. 2011 Jun 17;4:110. doi: 10.1186/1756-3305-4-110.
Malaria vector intervention and control programs require reliable and accurate information about vector abundance and their seasonal distribution. The availability of reliable information on the spatial and temporal productivity of larval vector habitats can improve targeting of larval control interventions and our understanding of local malaria transmission and epidemics. The main objective of this study was to evaluate two methods of estimating larval habitat productivity in the western Kenyan highlands, the aerial sampler and the emergence trap.
The study was conducted during the dry and rainy seasons in 2008, 2009 and 2010. Aerial samplers and emergence traps were set up for sixty days in each season in three habitat types: drainage ditches, natural swamps, and abandoned goldmines. Aerial samplers and emergence traps were set up in eleven places in each habitat type. The success of each in estimating habitat productivity was assessed according to method, habitat type, and season. The effect of other factors including algae cover, grass cover, habitat depth and width, and habitat water volume on species productivity was analysed using stepwise logistic regression
Habitat productivity estimates obtained by the two sampling methods differed significantly for all species except for An. implexus. For for An. gambiae s.l. and An. funestus, aerial samplers performed better, 21.5 and 14.6 folds, than emergence trap respectively, while the emergence trap was shown to be more efficient for culicine species. Seasonality had a significant influence on the productivity of all species monitored. Dry season was most productive season. Overall, drainage ditches had significantly higher productivity in all seasons compared to other habitat types. Algae cover, debris, chlorophyll-a, and habitat depth and size had significant influence with respect to species.
These findings suggest that the aerial sampler is the better of the two methods for estimating the productivity of An. gambiae s.l. and An. funestus in the western Kenya highlands and possibly other malaria endemic parts of Africa. This method has proven to be a useful tool for monitoring malaria vector populations and for control program design, and provides useful means for determining the most suitable sites for targeted interventions.
疟疾媒介干预和控制项目需要有关媒介丰度及其季节性分布的可靠和准确信息。关于幼虫媒介栖息地时空生产力的可靠信息可提高幼虫控制干预措施的针对性，并增进我们对当地疟疾传播和流行的了解。本研究的主要目的是评估两种在肯尼亚西部高地估计幼虫栖息地生产力的方法，即空中取样器和诱捕器。
该研究于 2008、2009 和 2010 年旱季和雨季进行。在每个季节的 60 天内，在三种生境类型（排水渠、天然沼泽和废弃金矿）中设置了空中取样器和诱捕器：排水渠、天然沼泽和废弃金矿。在每个生境类型中设置了 11 个空中取样器和诱捕器。根据方法、生境类型和季节评估每种方法在估计生境生产力方面的成功程度。使用逐步逻辑回归分析了其他因素（包括藻类覆盖、草覆盖、生境深度和宽度以及生境水量）对物种生产力的影响。
除 An. implexus 外，两种采样方法获得的生境生产力估计值在所有物种上均有显著差异。对于 An. gambiae s.l. 和 An. funestus，空中取样器的性能分别比诱捕器好 21.5 倍和 14.6 倍，而诱捕器对于库蚊物种则更为有效。季节性对所有监测物种的生产力均有显著影响。旱季是最具生产力的季节。总体而言，在所有季节中，排水渠的生产力均明显高于其他生境类型。藻类覆盖、碎片、叶绿素-a 以及生境深度和大小对物种均有显著影响。
这些发现表明，在肯尼亚西部高地和可能的非洲其他疟疾流行地区，空中取样器是估计 An. gambiae s.l. 和 An. funestus 生产力的两种方法中更好的方法。该方法已被证明是监测疟疾媒介种群和设计控制项目的有用工具，并为确定有针对性干预措施的最适地点提供了有用手段。
