An Anopheles gambiae mosquito
NIAID-funded researchers are investigating an innovative approach to stop malaria – killing the parasites inside mosquitoes before they can be transmitted to humans. According to the World Health Organization, there were an estimated 249 million cases of malaria and 608,000 deaths from the disease in 2022. With no approved vaccines, insecticide-treated bed nets have been a critical tool for preventing malaria infections. However, mosquitoes have developed widespread resistance to insecticides, threatening the continued success of the intervention.
Researchers are exploring a new a way to enhance the use of bed nets. Instead of treating the bed nets with insecticides, investigators are examining whether coating bed nets with an antimalarial drug can prevent the development of parasites within mosquitoes.
A NIAID-funded research team, led by scientists at Harvard University, exposed Anopheles gambiae mosquitoes, the main vectors of malaria in Africa, to low concentrations of atovaquone (a malaria drug). The team coated the surface of a petri dish with atovaquone, then allowed female An. gambiae mosquitoes to land on the surface before feeding them a blood meal infected with Plasmodium falciparum, one of the parasites responsible for malaria. The study found that the antimalarial drug, after being absorbed through the mosquito's legs, was able to reach the mosquito's stomach and completely block parasite development.
When incorporating the results of this work into a malaria transmission model, findings indicated that treating bed nets with an antimalarial, such as atovaquone, could significantly counteract mosquito insecticide resistance as well as transmission of malaria to humans. Research is ongoing to determine the feasibility of this approach.