MOSQUITOES have genetically mutated to survive insecticide, scientists have found.
Malaria-carrying insects which can resist the long-banned pesticide DDT have been discovered in Tanzania for the first time.
Researchers from the University of Glasgow and Tanzania’s Ifakara Health Institute warn that this could harm humanity’s battle against malaria.
PhD student Joel Odero, the study’s lead author, said: “The emergence of new resistance mechanisms could threaten decades of progress made in reducing malaria transmission and mortality.”
Researchers tested mosquitoes from 10 regions across Tanzania and found that some had gained “knock-down resistance” to the pesticide DDT due to a genetic mutation called ‘L976F’.
Those collected from the Morogoro region only died 68% of the time after being exposed to the insecticide – compared to nearly 100% for other mosquitoes.
Their findings were published in Molecular Ecology.
It is the first time malaria-carrying anopheles funestus mosquitoes have been found to have developed knock-down resistance to any chemical treatment.
It comes after health officials last year warned that mosquitoes carrying deadly West Nile virus have developed immunity to some repellents.
The virus – which can cause fits and paralysis in severe cases – is spread by the Culex mosquito.
After a season of extreme heat and heavy stormy created ideal conditions for the pest to thrive, health officials in the US reported last year that one of the first lines of defence against it no longer seemed to be working.
Scientists at the Centers for Disease Control and Prevention warned that Culex mozzies have become increasingly resistant to the insecticides that communities use in mass sprays to try to kill the bugs and their eggs.
Mosquitoes can carry viruses which cause certain diseases like West Nile virus and the viruses that cause malaria, yellow fever and dengue fever.
The mosquito gets a virus or parasite by biting an infected person or animal, then transferring it to the next person through its saliva.
Mosquitos bite during both day and night, and they can live indoors.
There were more than 600,000 deaths from malaria in 2022, according to the World Health Organisation.
Malaria is spread by Anopheles mosquitoes, when they bite people to feed on their blood.
When the mosquitoes bite, they transfer the malarial parasites into the person’s bloodstream, causing them to become ill.
Only the female mosquito feeds on human blood, however.
In exceptionally rare circumstances the disease can also be spread by blood transfusions.
You can take several steps to protect yourself from mosquito bites, including wearing protective clothing, taking preventative medicines and vaccinations, and using insect repellent.
Source: Mayo Clinic
