The need for practical insecticide-resistance guidelines to effectively inform mosquito-borne disease control programs

Abstract

Monitoring local mosquito populations for insecticide resistance is critical for effective vector-borne disease control. However, widely used phenotypic assays, which are designed to monitor the emergence and spread of insecticide resistance (technical resistance), do not translate well to the efficacy of vector control products to suppress mosquito numbers in the field (practical resistance). This is because standard testing conditions such as environmental conditions, exposure dose, and type of substrate differ dramatically from those experienced by mosquitoes under field conditions. In addition, field mosquitoes have considerably different physiological characteristics such as age and blood-feeding status. Beyond this, indirect impacts of insecticide resistance and/or exposure on mosquito longevity, pathogen development, host-seeking behavior, and blood-feeding success impact disease transmission. Given the limited number of active ingredients currently available and the observed discordance between resistance and disease transmission, we conclude that additional testing guidelines are needed to determine practical resistance—the efficacy of vector control tools under relevant local conditions— in order to obtain programmatic impact.

Phenotypic insecticide resistance status of the Culex pipiens complex: a European perspective

“…pipiens . Genetic resistance assays are also used to monitor the insecticide resistance status of mosquitoes, however, not all genetic markers that are involved in insecticide resistance are known yet and the genetic markers that are known are not always fully able to explain the phenotypic resistance [ 56 ]. Literature reports indicate that the resistance status of Cx.…”

Plant-Based Bioinsecticides for Mosquito Control: Impact on Insecticide Resistance and Disease Transmission

“…There are also potential limitations to the efficacy of bioinsecticides, such as environmental conditions, mosquito fitness, mosquito resistance as well as the parts of the plants used, solvents used in extraction steps, insecticide dose and exposure time [190,191]. These effects should be considered for successful assessment of novel bioinsecticides in mosquito control.…”

Vector control: agents of selection on malaria parasites?

“…Due to the wealth of knowledge about the effects of insecticide-based VCTs on Anopheline vectors of malaria, we focus on this system, but the concepts will be generalisable to other vector-borne infectious diseases and other VCTs, including tools currently in development, such as gene drives and endectocides (compounds administered to mammalian hosts to render blood meals toxic to mosquitoes) [11,12]. Moreover, opening the black box of parasite-vector interactions may reveal how to make VCTs robust to clinically and epidemiologically unfavourable parasite counter-evolution as well as uncover new approaches for VCTs.…”