Scientists have made a groundbreaking discovery that could revolutionise the fight against mosquitoes in rural Africa. A lotion derived from catnip has been found to be as effective as the widely used chemical Deet in repelling these biting insects, according to new research presented at the Society for Experimental Biology conference in Florence.
The study, conducted by a team of researchers from Uganda and Cardiff University in Wales, focused on Nepeta cataria, commonly known as catnip. The active compound responsible for its insect-repelling properties is nepetalactone. While previous studies have highlighted nepetalactone's potential as an insect repellent, this research marks a significant step towards its commercialisation.
Dr. Simon Scofield, a senior lecturer at Cardiff University, explained the practical implications of their findings. He noted that a 6% catnip oil formulation was found to be as effective as Deet, with a 2% concentration only marginally less so. This is particularly crucial in regions like rural Uganda, where the high cost of commercially available Deet-based repellents makes them inaccessible for many subsistence farmers. The project aims to create an affordable and locally produced repellent that can be made accessible to those who need it most.
The study involved both laboratory tests and field trials in eastern Uganda. Researchers observed how many mosquitoes landed on volunteers' legs over an evening, comparing the efficacy of a 2% catnip lotion, a 6% catnip lotion, a 15% Deet lotion (the most common strength in Uganda), and placebo creams. The results consistently showed the catnip formulations to be highly effective.
According to the World Health Organisation, malaria is a significant public health concern in Africa, with approximately 282 million people infected annually and 610,000 deaths reported in 2024, predominantly among young children. Increasing resistance to existing insecticides and frontline malaria drugs is also a growing concern. The potential for local production of this catnip lotion offers hope for improved accessibility and affordability.
Swai Kyeba, a research entomologist at the Ifakara Health Institute in Tanzania, highlighted the importance of new, affordable, and locally produced vector-control tools to improve accessibility, although he noted challenges with compliance due to the need for regular application. The researchers' next phase aims to scale up production and sell the lotion, creating a sustainable income stream for local workers.