Scientists from the World Mosquito Programme have published new findings from research into the use of Wolbachia to control the spread of dengue via Aedes aegypti mosquitoes.

The research, published recently in the New England Journal of Medicine, found laboratory-reared Aedes mosquitoes infected with a naturally occurring non-harmful bacterium Wolbachia, resulted in a 77 percent decline in dengue cases in trial areas within Yogyakarta city in Indonesia, where the treated mosquitoes were released.

This approach has been shown to be effective because the males of these treated mosquitoes pass on the Wolbachia to wild females they mate with, and the subsequent generations continue to spread the Wolbachia bacteria, which have the ability to inhibit viral reproduction but with no negative environmental impact. The Wolbachia-infected mosquitoes become self-sustaining, causing a rapid reduction in the prevalence of dengue virus.

Why is dengue a problem?

Dengue is a mosquito-borne virus that for several decades has been steadily increasing its spread and impact across the tropical and sub-tropical belts of the world, and will continue to extend its reach, especially into lower-income settings. Around 400 million cases are now registered each year, compared to 15,000 cases in 1960. The mosquitoes that carry dengue, certain species of the Aedes group, are the same mosquitoes that carry Zika, chikungunya, yellow fever, and others, and these viruses are also on a trend to rising global impact. The speed at which dengue is growing around the world has underlined the need for more research into the disease and its vectors.