Community-level impacts of spatial repellents for control of diseases vectored by Aedes aegypti mosquitoes

Spatial repellents (SRs) reduce human-mosquito contact by preventing mosquito entrance into human-occupied spaces and interfering with host-seeking and blood-feeding. A new model to synthesize experimental data on the effects of transfluthrin on Aedes aegypti explores how SR effects interact to impact the epidemiology of diseases vectored by these mosquitoes. Our results indicate that the greatest impact on force of infection is expected to derive from the chemical’s lethal effect but delayed biting and associated negative feedbacks on the vector population could elicit substantial impact in the absence of lethality. The relative contributions of these effects depend on coverage, chemical dose, mechanism of action, and housing density. We also demonstrate potential adverse impacts of increased partial blood-feeding and reduced exiting, which could offset gains achieved by other effects. Our analysis demonstrates how small-scale experimental data can be leveraged to derive expectations of epidemiological impact of SRs deployed at larger scales.