'Groundbreaking' mosquito hack trial cuts dengue by 77%

Representative image: An aedes aegypti mosquito with the dengue-blocking Wolbachia bacteria is seen inside a laboratory tube before being released.

Dengue fever cases have been cut by 77 percent in a “groundbreaking” trial that manipulates mosquitoes that spread it, scientists said. The development boosts hope of eradicating the virus that infects 390 million people around the world each year.

Scientists used mosquitoes infected with “miraculous” bacteria called “Wolbachia”. The bacteria cut the insect's ability to spread the infection.

The trial was carried out in Indonesia’s Yogyakarta city and is being expanded.

As many as 141 countries are affected by dengue fever, but the most significant dengue epidemics in recent years have occurred in Southeast Asia, the Western Pacific and the Americas. Over 40 percent of the world’s population is at risk of getting infected, according to the World Mosquito Programme.

Each year, the disease leads to 25,000 deaths annually worldwide.

The World Mosquito Programme said that the results of its three-year randomised controlled trial provide “compelling gold standard evidence” for the efficacy of the Wolbachia method in controlling dengue.

The Trial

WMP and its partners conducted a Cluster Randomised Controlled Trial within a 26 square kilometre area of Yogyakarta.

The study’s aim was to determine whether deployment of Wolbachia-carrying Aedes aegypti mosquitoes leads to a drop in dengue cases in Wolbachia-treated as compared to untreated areas.

The study area was further divided into 24 clusters, among which 12 were randomly selected to receive Wolbachia mosquito releases along with regular dengue control measures. The remaining 12 continued to receive routine dengue control measures, WMP said.

“Following the successful establishment of Wolbachia, consenting patients presenting with fever were enrolled at a network of primary care clinics across the study area over a period of 27 months, and were tested for dengue,” WMP said.

Efficacy against hospitalised dengue was even higher at 86 percent, with only 13 hospitalisations for dengue in the Wolbachia-treated area compared to 102 in the untreated area, according to the peer-reviewed results published in The New England Journal of Medicine.