A species that transmits dengue and other diseases has developed a mutation that gives it greater resistance to chemicals. Photo: Shutterstock
A study led by Japanese researchers discovered the existence of mosquitoes more resistant to insecticides. To do this, they collected specimens of the species Aedes aegypti in Vietnam, Indonesia, Cambodia, Taiwan and Ghana, which they exposed to chemicals designed to kill or repel them. Thus, they confirmed that those who came from Vietnam and Cambodia had developed greater survivability.
According to the first installment of research published in Science Advancesonly 20% of mosquitoes collected in Vietnam died after being exposed to pyrethroid pesticides, while the percentage of deaths for the remainder was within expected figures.
Analysis of these “super moquitos” revealed that they had suffered a mutation in the L982W gene, which is associated with resistance.
The next step was to collect more samples in Cambodia and Singapore to examine their genes, and so they found ten strains with mutations similar to Vietnamese mosquitoes. Almost all of them were in specimens collected in Cambodia.
“I think our work will help us understand that evolution is a powerful force,” said Shinji Kasai, head of research, adding that Aedes aegypti “can live anywhere.”
The research team explained that by 78% of mosquitoes collected in Cambodia or Vietnam were resistant to the pyrethroid thanks to genetic mutation.
They also explained that those with one combination of the L982W gene mutation with another could survive an insecticide exposure 500 to 1,000 times the amount that would normally kill them.
Although the mosquito with the mutation has only been found in two countries so far, the researchers warned it could spread to other areas of Southeast Asia, where it could become an “unprecedented serious threat to the fight against dengue” and other diseases.
(With information from RT)