Insecticide Resistance Associated withkdrMutations inAedes albopictus: An Update on Worldwide Evidences

Abstract

Insecticide resistance is an increasing problem worldwide that limits the efficacy of control methods against several pests of health interest. Among them, Aedes albopictus mosquitoes are efficient vectors of relevant pathogens causing animal and human diseases worldwide, including yellow fever, chikungunya, dengue, and Zika. Different mechanisms are associated in conferring resistance to chemical insecticides. One of the most widespread and analysed mechanisms is the knockdown resistance (kdr) causing resistance to DDT and pyrethroids. The mechanism is associated with mutations in the voltage sensitive sodium channel, which is involved in beginning and propagation of action potentials in nervous cells. The mechanism was originally discovered in the housefly and then it was found in a large number of arthropods. In 2011, a kdr associated mutation was evidenced for the first time in A. albopictus and afterward several evidences were reported in the different areas of the world, including China, USA, Brazil, India, and Mediterranean Countries. This review aims to update and summarize current evidences on kdr in A. albopictus, in order to stimulate further researches to analyse in depth A. albopictus resistance status across the world, especially in countries where the presence of this vector is still an emerging issue. Such information is currently needed given the well-known vector role of A. albopictus in the transmission of severe infectious diseases. Furthermore, the widespread use of chemical insecticides for control strategies against A. albopictus progressively lead to pressure selection inducing the rise of insecticide resistance-related mutations in the species. Such event is especially evident in some countries as China, often related to a history of uncontrolled use of chemical insecticides. Thus, a careful picture on the diffusion of kdr mutations worldwide represents a milestone for the implementation of control plans and the triggering of novel research on alternative strategies for mosquito-borne infections.

Phenotypic and genotypic pyrethroid resistance ofAedes albopictus, with focus on the 2017 chikungunya outbreak in Italy

“…In fact, although the two mutations have not so far been observed in linkage in Ae. albopictus, their association was shown to lead to enhanced resistance in Ae. aegypti …”

First report of Aedes albopictus infected by Dengue and Zika virus in a rural outbreak in Brazil

“…Aedes albopictus was never associated with DENV and ZIKV transmission in Brazil, despite its recognition as a competent vector for at least 22 pathogens [8,9], with proven capacity to transmit both viruses [7,[9][10][11][12]. In this country, A. albopictus is present in all regions, including at least 59% of municipalities [13] and more than 24 states [14].…”

The need to harmonize insecticide resistance testing: methodology, intensity concentrations and molecular mechanisms evaluated inAedes aegyptipopulations in Central America and Hispaniola

“…As a matter of fact, permethrin has been one of the most widely used insecticides to control Ae. aegypti due, in part, to the market availability and lower cost (54, 55). That is not the case with etofenprox, a pseudo-pyrethroid that is seldom employed in vector control operations in the region; however, resistance levels to etofenprox were also documented in this study.…”