Scientist Engages in Battle with Mosquitoes

In a significant breakthrough, a team of researchers led by Cameroonian scientist Corine Ngufor have developed a new type of mosquito net that has shown remarkable effectiveness in combating malaria. The nets, known as Interceptor G2 (IG2) nets, are treated with a combination of pyrethroid and an insecticide called chlorfenapyr.

Between 1980 and 2000, malaria was responsible for the deaths of 800,000 to 900,000 people each year, with a majority of the victims being children. However, the use of bed nets treated with pyrethroid and indoor spraying with long-lasting insecticide significantly reduced malaria cases and deaths starting around 2005. Unfortunately, mosquitoes have developed resistance to pyrethroid, causing malaria cases and deaths to rise again in 2020.

One potential solution to combat insecticide resistance is creating dual-insecticide nets, and the IG2 nets have proven to be a promising solution. Initially, chlorfenapyr was not killing many mosquitoes in lab tests, but the team improved the product by considering real-world conditions and using experimental huts for testing. The team's tests in these experimental huts resulted in a significant number of dead mosquitoes, indicating the effectiveness of the dual-treated nets.

Corine Ngufor's lab, based in London, tested chlorfenapyr, an insecticide that acts differently than pyrethroids and blocks mosquitoes' energy production. After confirming the results of their tests, the lab shared their findings broadly. The IG2 nets were then tested in randomized controlled trials, including one in Benin that Corine Ngufor helped design.

In 2023, the World Health Organization made a strong recommendation in favor of the pyrethroid-chlorfenapyr nets over pyrethroid-only nets, based on their life-saving potential and cost-effectiveness. The IG2 nets performed significantly better than pyrethroid nets alone in a key study in Tanzania, cutting malarial infections among children by almost half.

Researchers found that the IG2 nets, despite costing more than pyrethroid-only ones, would actually save money in the long run by treating the malaria cases that would have arisen without them. A large pilot project in 17 countries found that the IG2 nets prevented 13 million malaria cases between 2019 and 2022, saving an estimated 25,000 lives.

The funding for the development of the Interceptor G2 networks was supported by the Bill & Melinda Gates Foundation, which continues to support research into new tools for malaria, including malaria vaccines and improved treatments. The foundation also supports the development of attractive targeted sugar baits, which kill mosquitoes after they take a drink of sugary liquid.

Corine Ngufor's work has played a significant role in developing a cost-effective innovation for exterminating more mosquitoes, helping to cut malaria cases among children almost in half. However, constant vigilance is critical as mosquitoes continue to adapt and may eventually adapt to chlorfenapyr. The Bill & Melinda Gates Foundation supports organizations that are developing more sophisticated monitoring systems to better track and target mosquito vectors.

Corine Ngufor holds a Ph.D. from the London School of Hygiene & Tropical Medicine and leads a lab that investigates mosquito control products across the African continent. Her work is a testament to the power of scientific research in addressing global health challenges and saving lives.