WHO approves new nets to combat resistant parasite: In places with parasite resistance, the World Health Organization advises using bed nets treated with new pesticides to prevent malaria.
To circumvent any resistance, the new guidelines mix pyrethroid with another substance.
WHO approves new nets to combat resistant parasite: Due of its projected “increased fatal impact,” the pesticide chlorfenapyr, which is strongly advocated in regions with pyrethroid resistance, is coupled with either pyrethroid or the insect growth regulator pyriproxyfen.
Chlorfenapyr “induces muscular cramping in mosquitoes,” which prevents them from flying, according to the London School of Hygiene & Tropical Medicine, whose researchers have led extensive trials of pyrethroid-chlorfenapyr-treated bed nets in Tanzania and Benin.
This results in their death since they are unable to move or eat, as they are stuck to the place.
Throughout 15 years, chlorfenapyr was the subject of research. According to Manfred Accrombessi, assistant professor of epidemiology at LSHTM and the trial manager in Benin, the COVID-19 pandemic also had an effect on the studies, causing them to take longer to finish.
In both studies, malaria infections were significantly lower than with conventional pyrethroid bed nets.
After 24 months of the Tanzania experiment, malaria prevalence was lower in children who got bed nets treated with pyrethroid and chlorfenapyr: 25.6% versus 45.8% in those who received bed nets treated alone with pyrethroid.
The Benin trial’s results were comparable. Following 18 months, malaria incidence in the group that got bed nets treated with pyrethroid and chlorfenapyr was only at 27.9% compared to 38.7% in the group that received bed nets treatment simply with pyrethroid.
LSHTM claims that the results of the experiments represent “the first demonstration in 40 years of a novel, safe, and effective pesticide for use on nets.”
What is the next step?
Researchers expect the distribution of the new bed nets in malaria-endemic regions in accordance with WHO standards. According to Accrombessi in Benin, it can occur as soon as in the following two months.
He is aware of the difficulties in getting new bed nets adopted by communities, though. Families did not utilise the new nets they received right away; instead, they continued to use their old nets until they needed to be replaced, which was one of the things they saw throughout the experiment in Benin.
One month following the distribution, “we did a net coverage utilisation survey, and it was roughly 52% of the community utilising the new nets,” Accrombessi said.
This prompted them to launch follow-up activities to make sure families were using the new nets.
According to Accrombessi, the possibility of providing a family with more than one net in order to enhance uptake and remove the old ones in exchange is being considered.
This applies to houses where families who don’t all sleep in the same room. But they still need to determine whether or not it is feasible.
Obtaining nets coated with pyrethroid and chlorfenapyr costs $3.02, which is significantly more than pyrethroid-only bed nets, which cost $2.07. But, according to studies, savings from fewer malaria cases might cover the expense.
To ensure the long-term effectiveness of the new nets, Accrombessi said the focus should now be on creating a thorough long-term resistance management plan, something that was lacking when pyrethroid-only bed nets were implemented.