The deadliest animal on the planet could be destroyed by a simple household product, scientists say.
Mosquitoes kill more people that any other animal in the world by spreading diseases like malaria, dengue, West Nile virus and yellow fever, to name a few. Controlling mosquito populations is therefore essential for public health. However, many of the available insecticide solutions—which rely on harsh, synthetic chemicals—are becoming ineffective.
"The problem is resistance or adaptation of target mosquito populations to several classes of chemical pesticides," Colince Kamdem, an assistant professor in biological sciences at the University of Texas at El Paso, told Newsweek. "Some populations can survive exposure to 10 times the dose of insecticide that kill susceptible mosquitoes."
The resistant mosquitoes are a particular concern in regions like Sub-Saharan Africa, which carries a disproportionately high share of the 247 million malaria cases reported by the World Health Organization every year.
"Insecticide resistance threatens to hinder the progresses achieved in the reduction of malaria burden in Sub-Saharan Africa," Kamdem said. "The development of more potent chemicals is urgently needed to strengthen mosquito control programs."
A special class of insecticides called neonicotinoids has shown promise in laboratory tests and field trials as a second defense against resistant mosquitoes. But not all species of mosquito are susceptible to these chemicals. At least not on their own.
In a study published on November 17 in the journal PLOS Neglected Tropical Diseases, Kamdem and his team set about finding a simple and effective method to increase the potency of this class of insecticides. And what they found was that the addition of simple bathroom soap could increase the potency of neonicotinoids by more than 10-fold.
"The mechanisms of interaction between soap and pesticides remain unclear," Kamdem said. "Based on our knowledge of the chemical properties of surfactants contained in liquid soap, these substances likely solubilize some insecticides and reduce the thickness of the insect cuticle, allowing more pesticide to reach its target in the tissues."
All three brands of soap increased mosquito mortality from 30 percent to 100 percent compared to when the insecticides were used on their own. However, the same effects were not seen when the soaps were combined with a different class of insecticides known as pyrethroids.
The soaps used in the study all contained a compound made from seed oil, but Kamdem said other oils like vegetable oil might also be effective when combined with neonicotinoids.
"The generalization of our findings remains to be tested," he said.
The team hopes to use the findings to create a more effective, low-cost insecticide formula.
"We would love to make a soap-insecticide formulation that can be used indoors in Africa and be healthy for users," Kamdem said. "There are unknowns as to whether such a formulation will stick to materials like mosquito nets, but the challenge is both promising and very exciting."
Uncommon Knowledge
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Pandora Dewan is a Senior Science Reporter at Newsweek based in London, UK. Her focus is reporting on science, health ... Read more
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