Vector Control and Insecticide Resistance
Written by Maggie Bauer
Edited by Tanishq Vaidya
February 9th, 2023
Edited by Tanishq Vaidya
February 9th, 2023
Research
What do you think of when you hear the word mosquito? Most people would think about the annoying buzzing sound or the bug bites that result, but they can also have much more harmful effects. Mosquitos are one of the most well known and widespread vectors of disease for many common illnesses such as malaria and zika. A vector is a species that transmits diseases between hosts and includes mosquitos, flies, ticks, and many other organisms (2). Their potential for causing an outbreak has raised concerns for epidemiologists worldwide.
The primary method of combating vectors is through spraying insecticides. Insecticides vary in their mode of action, but all serve the purpose of reducing the insect population. A new concern in vector control is the rise of insecticide resistance, which causes these insecticides to be virtually ineffective. Natural selection works on these resistance traits just like it would work on any other. If the trait provides a benefit to the organism, it will be selected for therefore raising the prevalence of this trait. So as people continuously spray insecticides into the insect population, all the non-resistant members die off providing a huge increase in fitness to those organisms with the resistance trait.
In this study, data was compiled from several countries to see general trends in insecticide use1. The results showed that the insecticides were most commonly used in combating malaria with around “60.8%” of insecticide use dedicated for this purpose1. The efforts to control the disease, dengue, Chagas disease, and leishmaniasis, were found to have the most issues in terms of insecticide resistance management (1). The results were for the overall data collected but there was a lot of variation between countries (1). Due to the differences in infrastructure and strength of government policies, reactions to incidents of resistance and data about the techniques employed greatly varied. In general, it is standard practice to eliminate the usage of a particular insecticide if resistance to it is detected, but many governments were slow to react (1). This is a problem since continued application of insecticide could exacerbate the problem by further eliminating the non-resistant members and creating a purely resistant population. Surprisingly, solutions such as using different insecticides before resistance developed also proved to be ineffective (1).
From this study, we can learn many lessons based on the programs and subsequent results from different countries’ response to mosquito resistance. The conclusions made reflected the importance of government communication on emerging problems and quick solutions to those problems in order to create effective control strategies. They also emphasized the importance of vector control in monitoring and controlling vector populations. The article also stressed the need for new ideas and methods of vector control that either reduce risk of insecticide resistance or don’t require insecticides at all.