Insecticide Resistance in Insect Vectors of Disease with Special Reference to Mosquitoes: A Potential Threat to Global Public Health

Context: Arthropod-borne diseases are remaining as a major public health issue in the resource-constrained settings. Mosquitoes are closely associated with mankind since time immemorial and play an important role in the transmission of many dreadful diseases like malaria, filariasis, Japanese encephalitis, dengue and yellow fever. Over the decades, vector control is an important element to minimize the vector-borne disease burden worldwide and in fact, it heavily relies upon synthetic insecticides as a mainstay. However the overuse and misuse of insecticides have led to the emergence of resistance, which undermines the potentiality of vector control. Evidence Acquisition: In order to pursue effective research pertained to this issue, a detailed search on Scopus, Medline, Google Scholar and academic premier databases has been conducted between the time periods of 1955 and 2012. Over the past six decades, insecticides are serving as one of the important arsenals in the fight against vector-borne diseases to save hundreds of millions of lives. Consequently, in the last decade we have attained a remarkable success to combat with many diseases particularly malaria due to the combined effect of indoor residual spraying (IRS) and long-lasting insecticidal nets (LLINs). Currently, malaria mortality rates have drastically fallen by more than 25% globally, 33% in sub-Saharan Africa and over a million lives have been saved attributable tomassive scale-up of LLINs and IRS. Since, both LLINs and IRS are cost-effectiveand robust form of interventions; they are serving as a central pillar in the National Malaria Control Programmes (NMCPs) of malaria endemic countries. Nevertheless, LLINs are easy-to-deliver, most economical and practical even in the resource-poor settings, where implementation of IRS is not feasible. The heavy reliance, recurrent and inappropriate insecticide applications are key sources for resistance which is a potential threat to the global public health. Therefore, it has to be addressed immediately to sustain the recent success of vector control, unless otherwise it would become uncertain. Though, development of resistance is an evolutionary phenomenon, it can be tackled judiciously by implementing appropriate and comprehensive resistance monitoring and management strategies within the framework of integrated vector management. This scrutiny recommends the following measures; (i) identification of effective novel tools for monitoring and evaluation, (ii) searching for alternative interventions to minimize the further resistance evolution as well as to preserve the efficiency of existing insecticides, (iii) exploration of next generation vector control tools in terms of nets and new classes of non-pyrethroid insecticide formulation with new mode of action, (iv) building partnership by bringing together the people actively engaged in the vector control, like public health experts, policy-makers, researchers, medical entomologists and insecticide manufacturers, could ideally pave the way to collectively address the current debacle in the near future.