Department of Infectious Disease Epidemiology, MRC Centre for Outbreak Analysis and Modelling, Imperial College London, London, UK.
Malar J. 2013 Aug 23;12:291. doi: 10.1186/1475-2875-12-291.
Current vector control strategies focus largely on indoor measures, such as long-lasting insecticide treated nets (LLINs) and indoor residual spraying (IRS); however mosquitoes frequently feed on sugar sources outdoors, inviting the possibility of novel control strategies. Attractive toxic sugar baits (ATSB), either sprayed on vegetation or provided in outdoor bait stations, have been shown to significantly reduce mosquito densities in these settings.
Simple models of mosquito sugar-feeding behaviour were fitted to data from an ATSB field trial in Mali and used to estimate sugar-feeding rates and the potential of ATSB to control mosquito populations. The model and fitted parameters were then incorporated into a larger integrated vector management (IVM) model to assess the potential contribution of ATSB to future IVM programmes.
In the Mali experimental setting, the model suggests that about half of female mosquitoes fed on ATSB solution per day, dying within several hours of ingesting the toxin. Using a model incorporating the number of gonotrophic cycles completed by female mosquitoes, a higher sugar-feeding rate was estimated for younger mosquitoes than for older mosquitoes. Extending this model to incorporate other vector control interventions suggests that an IVM programme based on both ATSB and LLINs may substantially reduce mosquito density and survival rates in this setting, thereby substantially reducing parasite transmission. This is predicted to exceed the impact of LLINs in combination with IRS provided ATSB feeding rates are 50% or more of Mali experimental levels. In addition, ATSB is predicted to be particularly effective against Anopheles arabiensis, which is relatively exophilic and therefore less affected by IRS and LLINs.
These results suggest that high coverage with a combination of LLINs and ATSB could result in substantial reductions in malaria transmission in this setting. Further field studies of ATSB in other settings are needed to assess the potential of ATSB as a component in future IVM malaria control strategies.
目前的病媒控制策略主要集中在室内措施上，如长效驱虫蚊帐（LLIN）和室内滞留喷洒（IRS）；然而，蚊子经常在户外吸食含糖的食物源，这为新的控制策略提供了可能性。诱捕含糖毒饵（ATSB），无论是喷洒在植被上还是提供在户外诱捕站中，都已被证明可以显著降低这些环境中的蚊子密度。
根据马里 ATSB 现场试验的数据，对蚊子吸食糖的行为进行了简单的模型拟合，并用于估计糖的吸食率和 ATSB 控制蚊子种群的潜力。然后，将模型和拟合参数纳入一个更大的综合病媒管理（IVM）模型中，以评估 ATSB 对未来 IVM 计划的潜在贡献。
在马里的实验环境中，该模型表明，每天约有一半的雌性蚊子吸食 ATSB 溶液，在摄入毒素后数小时内死亡。使用一个包含雌性蚊子完成的生殖周期数量的模型，估计年轻蚊子的糖摄入量高于年老蚊子。将这个模型扩展到包含其他病媒控制干预措施，表明基于 ATSB 和 LLIN 的 IVM 计划可能会显著降低该环境中的蚊子密度和存活率，从而大大降低寄生虫传播。这预计将超过 LLIN 与 IRS 联合使用的影响，前提是 ATSB 的摄食率达到马里实验水平的 50%或更高。此外，ATSB 预计对相对嗜外的按蚊（Anopheles arabiensis）特别有效，因为 IRS 和 LLIN 对其影响较小。
这些结果表明，在这种环境中，结合使用 LLIN 和 ATSB 的高覆盖率可能会导致疟疾传播的大幅减少。需要在其他环境中进一步开展 ATSB 的实地研究，以评估 ATSB 作为未来 IVM 疟疾控制策略的组成部分的潜力。
