The type of pesticide used on bed nets to prevent malaria has been revised by the World Health Organization (WHO).
The WHO now advises that areas with pyrethroid-resistance should instead employ pyrethroid-chlorfenapyr ITNs due to the developing resistance of disease-carrying Anopheles mosquitoes to pyrethroid, the insecticide currently used in insecticide-treated nets (ITNs).
The guidelines are supported by more than 15 years of study by the London School of Hygiene & Tropical Medicine (LSHTM) and collaborators, including findings from two sizable randomized trials.
Results from Tanzania and Benin, two nations with high levels of pyrethroid-resistant mosquitoes, backed the life-saving potential of chlorfenapyr-treated ITNs. This is the first time in 40 years that a new, safe, and efficient insecticide for use on nets has been demonstrated.Dr. Manfred Accrombessi, trial manager in Benin and assistant professor of epidemiology at LSHTM, stated: “The studies conducted in Tanzania and Benin offer enough proof to support the widespread use of nets treated with the insecticides chlorfenapyr and pyrethroid. To prevent making the same mistakes twice, this new generation bed nets should be used in conjunction with a thorough, long-term resistance management strategy.”
Associate Professor of Medical Entomology at LSHTM, Dr. Corine Ngufor continued: “The development of this WHO guideline over the course of over 20 years of research and invention marks a significant turning point in the fight against malaria. In the upcoming years, it is anticipated that these nets would be widely distributed throughout nations with endemic malaria. This will aid in the fight against malaria.
“All possible measures should be taken to protect their efficacy and to remove obstacles to continuous vector control innovation.”ITNs are one of the main control strategies for malaria prevention. These nets are treated with insecticides as they are manufactured, acting as a physical barrier that can also repel and kill disease-carrying mosquitoes.
Until now, ITNs containing only pyrethroid, an insecticide that kills mosquitoes by interfering with their nervous system, were the recommended intervention by the WHO in all areas where malaria is endemic, notably in sub-Saharan Africa.
