Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, SL5 7PY, UK.
Parasit Vectors. 2021 Sep 8;14(1):462. doi: 10.1186/s13071-021-04975-0.
While insecticide-based vector control can effectively target vector species in areas of high malaria endemicity, such as Anopheles gambiae in Africa, residual disease transmission can occur. Understanding the potential role of competitive displacement between vector species could inform both current insecticide-based vector control programmes and the development of future complementary interventions.
A systematic review was conducted to identify published studies of insecticide-based vector control of Anopheles species in Africa that reported indices for absolute densities of vector species. After screening against inclusion, exclusion and risk of bias criteria, studies were assigned to three categories based on whether they showed population density changes involving decreases in two or more vector species (D), increases in two or more vector species (I), or increases in one vector species concomitant with decreases in another vector species (ID). Category ID studies could thus provide evidence consistent with the release of vector species from competition following the insecticide-based population suppression of Anopheles species.
Of 5569 papers identified in searches, 30 were selected for quantitative and qualitative analysis. Nineteen studies were assigned to category D and one to category I. Ten studies categorised as ID provided evidence ranging from weak to persuasive that release from competition could have contributed to changes in species composition. Category ID showed no statistical differences from category D for reductions in malaria transmission and levels of insecticide resistance, but did so for insecticide type, pyrethroids being associated with category ID. A qualitative assessment identified five studies that provided the most convincing evidence that release from competition could have contributed to changes in species composition.
This review identified evidence that insecticide-based reductions in the density of Anopheles species in Africa could facilitate the release of other vector species from competition. While it remains uncertain whether this evidence is representative of most entomological sequelae of insecticide-based vector control in the field, five studies provided persuasive evidence that insecticide use could lead, at least under some circumstances, to competitive release of non-targeted vector species. These results should inform current and future integrated vector management approaches to malaria control.
虽然基于杀虫剂的病媒控制可以有效地针对疟疾高度流行地区的病媒物种（如非洲的冈比亚按蚊），但仍可能发生残留疾病传播。了解病媒物种之间竞争替代的潜在作用，可以为当前基于杀虫剂的病媒控制计划以及未来互补干预措施的制定提供信息。
进行了系统评价，以确定已发表的关于非洲基于杀虫剂的疟疾病媒控制的研究报告，这些研究报告报告了疟疾病媒物种的绝对密度指数。在经过纳入、排除和偏倚风险标准的筛选后，根据是否显示涉及两种或更多病媒物种减少（D）、两种或更多病媒物种增加（I）或一种病媒物种增加而另一种病媒物种减少（ID）的种群密度变化，将研究分为三类。因此，类别 ID 研究可以提供与在基于杀虫剂的疟疾病媒种群抑制后，病媒物种从竞争中释放相一致的证据。
在搜索中确定了 5569 篇论文，其中 30 篇被选中进行定量和定性分析。19 项研究被归类为 D 类，1 项为 I 类。10 项归类为 ID 的研究提供了从弱到有说服力的证据，表明竞争释放可能导致物种组成的变化。类别 ID 在减少疟疾传播和抗药性水平方面与 D 类没有统计学差异，但在杀虫剂类型方面，拟除虫菊酯与类别 ID 相关。定性评估确定了五项最有说服力的研究，这些研究提供了最有说服力的证据表明，竞争释放可能导致物种组成的变化。
本综述确定了证据表明，在非洲减少按蚊密度可以促进其他病媒物种从竞争中释放出来。虽然目前尚不确定这种证据是否代表了现场基于杀虫剂的病媒控制的大多数昆虫学后果，但五项研究提供了有说服力的证据表明，杀虫剂的使用至少在某些情况下会导致非目标病媒物种的竞争释放。这些结果应告知当前和未来的综合病媒管理方法来控制疟疾。
