Long-term dengue control in a hyperendemic setting following city-wide Wolbachia deployment: a post-intervention enhanced surveillance study in Yogyakarta, Indonesia

Effective, sustainable, scalable interventions are needed to address escalating global dengue outbreaks. Introduction of Wolbachia ( w Mel) into Aedes aegypti populations reduces dengue incidence, but evidence on long-term impacts following city-wide deployment is limited. We conducted a prospective enhanced surveillance study in Yogyakarta, Indonesia - the first dengue-endemic city to achieve sustained city-wide Wolbachia establishment - beginning two years after releases were completed in January 2021. Using routine dengue notifications, clinic-based virological surveillance, spatial analyses, and population-level serology, we demonstrate sustained reductions in dengue transmission and case incidence up to seven years post-release. Incidence during the five years following city-wide deployment was lower than any equivalent period in the preceding three decades, and dengue seroprevalence among children <10 years was more than halved compared with the pre-intervention period. Virologically confirmed cases in 2024 indicated residual local transmission with co-circulation of multiple serotypes during an unprecedented global epidemic. These findings demonstrate sustained dengue suppression, though not elimination, supporting Wolbachia as a key component of integrated dengue control strategies.