Management of insecticide resistance in the major Aedes vectors of arboviruses Advances and challenges

Background The landscape of mosquito-borne disease risk has changed dramatically in recent decades, due to the emergence and reemergence of urban transmission cycles driven by invasive Aedes aegypti and Ae. albopictus. Insecticide resistance is already widespread in the yellow fever mosquito, Ae. Aegypti; is emerging in the Asian tiger mosquito Ae. Albopictus; and is now threatening the global fight against human arboviral diseases such as dengue, yellow fever, chikungunya, and Zika. Because the panel of insecticides available for public health is limited, it is of primary importance to preserve the efficacy of existing and upcoming active ingredients. Timely implementation of insecticide resistance management (IRM) is crucial to maintain the arsenal of effective public health insecticides and sustain arbovirus vector control. Methodology and principal findings This Review is one of a series being generated by the Worldwide Insecticide resistance Network (WIN) and aims at defining the principles and concepts underlying IRM, identifying the main factors affecting the evolution of resistance, and evaluating the value of existing tools for resistance monitoring. Based on the lessons taken from resistance strategies used for other vector species and agricultural pests, we propose a framework for the implementation of IRM strategies for Aedes mosquito vectors. Conclusions and significance Although IRM should be a fixture of all vector control programs, it is currently often absent from the strategic plans to control mosquito-borne diseases, especially arboviruses. Experiences from other public health disease vectors and agricultural pests underscore the need for urgent action in implementing IRM for invasive Aedes mosquitoes. Based on a plan developed for malaria vectors, here we propose some key activities to establish a global plan for IRM in Aedes spp.
Author summary Arthropod-borne viruses transmitted by Aedes aegypti and Ae. albopictus represent a major public health concern at a global scale. The insecticidal treatments exerted on both species have selected for various resistance mechanisms within wild populations. Although the impact of insecticide resistance on the efficacy of vector control operations remains broadly unknown, it is of primary importance to implement strategies for preserving the efficacy of treatments and reducing the pathogen transmission during epidemics. For this purpose, there are urgent needs for new tools for vector control and insecticide resistance monitoring to improve the management of insecticide resistance in Aedes species.