Efficacy of Wolbachia-mediated sterility to suppress adult Aedes aegypti populations

Incompatible insect technique coupled with sterile insect technique (IIT-SIT) via releases of sterile male Wolbachia -infected mosquitoes is a promising tool for dengue control. In a six-year trial from 2016 to 2022, comprising 10.35 km2 of high-rise housing estates and 607,872 residents, we designed a synthetic control study methodology to assess the efficacy of IIT-SIT in reducing adult female Aedes aegypti populations, using data from a large, routinely collected, nationwide surveillance system of 57,990 unique mosquito traps in public housing estates. We demonstrated that Wolbachia -based IIT-SIT dramatically reduces wildtype Aedes aegypti populations by an average of 60.64% (95% CI: 59.59%–61.44%) and 79.37% (95% CI: 78.85%–79.87%) in 3, 6 months of releases and eventually 90.17% (95% CI: 89.92%–90.42%) in 12 and more months of releases. We further found a smaller but non-negligible suppression effect which gradually increased over time (47.91%, 95% CI: 47.29%–48.52%) in adjacent, non-intervention sites. Our results demonstrate the potential of IIT-SIT for strengthening dengue control in tropical cities, where dengue burden is the greatest. ### Competing Interest Statement Evidoxia Kakani is a paid employee of Verily Life Sciences. Du Yu is a paid employee of Orinno Technology, Singapore. All other authors declare no competing interests. ### Funding Statement This study was supported by funding from Singapore's Ministry of Finance, Ministry of Sustainability and the Environment, National Environment Agency, and National Robotics Program. JTL is supported by the Ministry of Education (MOE), Singapore Start-up Grant. SB and ARC are supported by an MOE Tier 2 grant. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors