TOPLINE:

The release of sterile Wolbachia-infected male Aedes aegypti mosquitoes reduced the risk for symptomatic laboratory-confirmed dengue by at least 71% after exposure of 3 months or more and lowered vector populations.

METHODOLOGY:

• Researchers conducted a cluster randomized trial in Singapore from 2022 to 2024 to assess whether the release of sterile male A aegypti mosquitoes infected with Wolbachia pipientis bacteria reduced the risk for dengue.
• The trial comprised 15 geographic clusters: Eight clusters received twice-weekly releases of sterile Wolbachia-infected male mosquitoes (intervention clusters, n = 8245), and seven clusters received no such releases (control clusters, n = 10,344); the overall mean age of the residents was 45.5 years, and 51.5% were male.
• One of the primary endpoints was diagnosis of symptomatic laboratory-confirmed dengue, assessed by comparing the exposure with Wolbachia-infected mosquitoes between residents with dengue and residents without dengue.
• Exposure was categorized by the minimum duration of exposure in an intervention cluster at the time of testing.
• Adult wild-type A aegypti populations were monitored using Gravitraps, with baseline abundance averaging 0.18 and 0.19 in the intervention and control clusters, respectively.

TAKEAWAY:

• Across randomized clusters, after at least 6 months of exposure, 6% vs 21% of residents in the intervention clusters vs control clusters tested positive for dengue.
• Residents in the intervention clusters were 71%-72% less likely to develop symptomatic dengue with 3-12 or more months of exposure to Wolbachia-infected mosquitoes (odds ratio, 0.28-0.29).
• The protective efficacy remained fairly constant across exposure durations and was consistent across age groups, sexes, and calendar years.
• By the end of the trial, the average abundance of wild-type A aegypti populations had decreased to 0.041 in the intervention clusters but had increased to 0.277 in the control clusters.

IN PRACTICE:

“[The release of sterile Wolbachia-infected male A aegypti mosquitoes] can complement conventional approaches and vaccination to further reduce and potentially eliminate dengue transmission, along with possibly other Aedes-borne diseases,” the authors of the study wrote.

SOURCE:

The study was led by Jue Tao Lim, PhD, Nanyang Technological University, Singapore. It was published online on February 11, 2026, in The New England Journal of Medicine.

LIMITATIONS:

The trial assessed exposure solely at the place of residence, although residents could have been exposed to dengue-transmitting mosquitoes outside the designated clusters. The trial was conducted in a setting with extensive mosquito control, potentially limiting generalizability to other locations. Despite using geographic borders and buffer sites, some wild-type mosquitoes could still have migrated between areas.

DISCLOSURES:

The study was supported by the Singapore Ministry of Finance, the Ministry of Sustainability and the Environment, the National Environment Agency, the National Robotics Programme, and a start-up grant from the Ministry of Education. The authors declared having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.