An overview of insecticide usage and resistance of insect vector to insecticide: An implication to public health

Abstract

Insecticides are highly effective when optimally implemented and crop damage from insect pest infestations and diseases transmitted by insect vectors often result in serious consequences, warranting the need to use insecticides. The main strategy for the elimination of insect vectors is the use of chemical insecticides. Since its discovery, chemical insecticides have represented the most widely method used to control insect vectors and insect pests. The use of insecticides has helped to reduce insect-borne diseases. However, despite their benefits, insecticides pose potential danger to public health when inappropriately handled. Almost all public health insecticide classes and nearly 90% of all insecticides worldwide are used for agricultural purposes. The insecticide resistance development in disease vectors are as a result of selection pressure due to agrochemicals and this occur in places where pesticides are more frequently applied, indiscriminately used and misused. Despite increasing concern about overuse and misuse of insecticides in developing countries, insecticide is still intensively used and the massive use of these chemicals have caused detrimental effects on the agroecosystem, such as the acquisition of resistance, pest resurgence/replacement, and environmental pollution. Insecticide resistance may increase insect’s vectorial capacity, which may lead to a dramatic increase in the transmission of the disease and even to a higher prevalence than in the absence of insecticides. Disease control failure, however follow from vector control failure. Increase in diseases transmission, mortality, injury to the crop and potential losses in crop production, disruption of biological control programmes and increase in management costs for additional chemical controls to prevent further injury are the consequences of insect resurgence, replacement and or resistance.