Multiple insecticide resistance mechanisms in primary dengue vector, Aedes aegypti (Linn.) from dengue endemic districts of sub-Himalayan West Bengal, India

Abstract

BackgroundMosquitoes belonging to genus Aedes are the prime vectors of several arboviral diseases such as Dengue, Zika and Chikungunya worldwide. Every year numerous cases of dengue infections occur throughout the world, proper control of which depends on efficient vector control. However the onset of insecticide resistance has resulted in failure of vector control approaches.Principal findingsThis study was carried out to unveil the degree of prevailing insecticide resistance along with its underlying mechanisms among the primary dengue vector in dengue endemic districts of West Bengal, India through standard WHO protocol. It was observed that, the majority of the tested populations were found to possess resistance to more than one insecticide. In adult bioassay, the toxicity levels of the six tested insecticides was found to decrease in the following order: deltamethrin > lambdacyhalothrin > malathion > propoxur > permethrin > DDT. In larval bioassay, one of the tested populations was found to possess moderate resistance against temephos, mortality percentage 92.5% and 79.8% for WHO (0.0200 ppm) and National Vector Borne disease Programme, India recommended dose (0.0125 ppm) respectively. Carboxylesterases were found to be involved in conferring resistance as revealed in synergistic and quantitative assay against temephos in North Dinajpur (NDP) population and malathion in Alipurduar (APD) and Darjeeling (DAR) populations. Similar correlations were also observed in the majority of the tested populations between reduced susceptibilities against pyrethroid insecticides and Cytochrome P450s activity.ConclusionEfficient disease management in this region can only be achieved through proper integrated vector management along with tools to minimize insecticide resistance. This study may help the concerned authorities in the formulation of an effective vector control strategy throughout this region incorporating the knowledge gained through this study.

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

“…As pirimiphos-methyl is scarcely used in the region, resistance to this product could be a cross-resistance phenomenon stemming from the continuous and wide spread use of temephos (26, 71, 72). Resistance to malathion and pirimiphos methyl have been reported elsewhere (21, 73–75), and in the LAC region (26, 36, 71, 76–81).…”

Malathion insecticide resistance inAedes aegypti: laboratory conditions andin situexperimental approach through adult entomological surveillance

“…The incidence of IR has increased rapidly in recent years [24] and is considered the main obstacle to successful control of Ae. aegypti [25]. It is a recurring phenomenon in different regions of the world where chemical control is a priority tool in vector control [12].…”

Evaluation of the resistance to insecticides in Aedes aegypti, transmitter of dengue, in Latin America

“…1 This is a disease caused by an RNA virus of the flavivirus genus of the family flaviridae 2 of which 4 serotypes are known to be transmitted by the bite of the female mosquito, mainly of the genus Aedes aegypti. 3 This vector is of great importance, since it is also the transmitter of other viral diseases such as yellow fever 4 , zika, chikungunya 5 and this can occur asymptomatically or in its severe forms; generating high rates of morbidity and mortality in the population. 6 In recent studies, a new serotype has been identified in the Asian continent, which follows the sylvatic cycle, which can be an indicator of the severity of the disease.…”

“…6 In recent studies, a new serotype has been identified in the Asian continent, which follows the sylvatic cycle, which can be an indicator of the severity of the disease. 5 In Southeast Asia, dengue represents more than 1.3 billion cases in the population, equivalent to 52% of people at risk around the world. One of the largest epidemics with 44,098 cases and 98 deaths happened in Lao in 2013.…”