Increase in Mosquitoes Resistant to Pesticides

As mentioned in the previous section, various measures have been taken worldwide to prevent the spread of mosquito-borne infectious diseases. Malaria outbreaks in Africa fell by 40% between 2000 and 2015, and it is estimated that more than 600 million people have been saved from infection over 15 years. Among them, pesticide-coated mosquito nets played a major role [1]. However, the number of mosquitoes that are resistant to pesticide components is increasing; that is, the number of mosquitoes that do not die even if pesticides are used is increasing.

A typical component of pesticides is a group of compounds called pyrethroids. These compounds act on the voltage-gated sodium channels expressed in mosquito neurons, causing abnormal neural excitation and killing mosquitoes. In resistant mosquitoes, the mosquito protein on which the pesticide component interacts is mutated and cannot be bound, or the cuticle that constitutes the surface of the mosquito has changed, making it difficult for the pesticide component to enter the body [2].