A new tool in the fight against malaria, called a spatial repellent, has shown significant promise in reducing malaria infections. The product, Mosquito Shield™, used in combination with insecticide-treated mosquito nets, demonstrated a reduction in malaria infections by one-third 32.1% overall and 33.4% for first-time infections compared to a placebo. This result marks a major advancement in malaria control, building on previous studies conducted in Indonesia, and is the first trial to show the impact of spatial repellents in reducing malaria transmission.
Spatial repellents, such as Mosquito Shield™, are designed to be placed on interior walls of living spaces. The product slowly releases an active ingredient that repels and immobilizes mosquitoes, preventing them from feeding on humans. It was tested in Busia County, Kenya, where malaria transmission remains high despite nearly universal use of insecticide-treated nets. This area faces a growing resistance to insecticides used in traditional vector control tools, making new solutions crucial.
The trial found that Mosquito Shield™ could complement existing malaria control measures, rather than replace them. This combination approach offers the potential for a substantial reduction in transmission, especially in areas where malaria remains a significant health threat. For every 100 people using Mosquito Shield™, an estimated 60 malaria infections could be prevented each year.
The success of Mosquito Shield™ has generated optimism about the future of malaria prevention. According to experts, the product’s effectiveness could lead to a significant reduction in malaria cases globally, saving tens of thousands of lives annually. The product is particularly beneficial for vulnerable populations, such as children, pregnant women, and displaced communities, who are at higher risk of malaria.
The trial was part of the Advancing Evidence for the Global Implementation of Spatial Repellents (AEGIS) project, which is funded by Unitaid and led by the University of Notre Dame, with additional support from the Kenya Medical Research Institute (KEMRI) and the U.S. Centers for Disease Control (CDC). The Kenyan Ministry of Health has already moved to incorporate spatial repellents into its national malaria control strategy, with guidelines for scaling up the use of spatial repellents already in development.
The success of Mosquito Shield™ in Kenya is seen as a key milestone in malaria control. The Kenyan Ministry of Health has taken steps to integrate the product into its broader malaria prevention efforts, particularly in regions with high transmission rates. This new tool offers hope for combating malaria in areas like Busia County, where malaria rates are comparable to those in countries with the highest burdens.
In addition to the trials in Kenya, the AEGIS project is conducting further studies in Mali and Sri Lanka to assess the product’s effectiveness against malaria and dengue, respectively. The Sri Lanka trial builds on earlier research showing that spatial repellents can significantly reduce the risk of dengue infection, offering further evidence of their potential in fighting mosquito-borne diseases.
The World Health Organization (WHO) requires evidence from two distinct settings to recommend a new product for use in malaria control. The results from the Kenya trial satisfy one of these criteria, and WHO is expected to review the findings in March 2024. If the results are approved, Mosquito Shield™ could become the first new class of vector control tool to be introduced in decades, further enhancing global efforts to eliminate malaria.
