Mosquitoes are responsible for the transmission of numerous life-threatening diseases including malaria, Rift Valley fever, dengue and Zika. Malaria in particular is very dangerous across some parts of the world, leading to 229 million cases and 400,000 deaths in 2019 alone. This disease is caused by parasites that can be transmitted through a mosquito bite.
Many control strategies have been put in place to reduce this threat including long-lasting insecticidal net programmes and indoor residual spraying. However, these intervention methods have their own problems. To start, mosquitoes are developing insecticide resistance, especially across Africa and it is quickly spreading worldwide. Second, these two methods, even when combined, are ineffective in areas with a high transmission rate.
As such, researchers are looking at new strategies that can improve the efficiency of current control methods. The key to creating these strategies is understanding why mosquitoes target certain people and not others.
The research began by studying what is in the chemical composition of the skin surface of certain individuals that attracted mosquitoes. Researchers have discovered two lines of further inquiry along this avenue. First, what are the chemical compounds that attract mosquitoes to an individual and which could be used in lures or traps, and second, which are the chemical compounds that repel mosquitoes which can be used to develop new repellents.
A female mosquito is first drawn to the carbon dioxide exhalation of a mammal, and once it is close enough to the body, it can detect heat emanating from it. Once it lands on the skin, the sensors on its feet can tell whether the body of the mammal holds suitable blood that is nutritious enough to sustain its egg producing needs.
The skin will secrete semiochemicals which the mosquito can detect. However, the complexity of the human skin surface poses a challenge for researchers looking to perform chemical analysis. Researchers have identified over 500 skin compounds in these secretions, with many more above that number remaining unknown.
The main priority right now is to identify as many of these compounds as possible, and figure out which of them act as attractants and repellents. The research is showing tremendous potential, not just for the objective of creating effective lures and repellents against mosquitoes, but also for developing skin sampling techniques that can be used in future research. For now however, we have to rely on classic control methods. Contact us today if you suspect that there may be a mosquito infestation on your property, and we will help you remove it.
