Long-term durability and public health impact of city-wide w Mel Wolbachia mosquito releases in Niterói, Brazil during a dengue epidemic surge

In 2024, the Americas region experienced the largest dengue outbreak on record and Brazil was among the worst affected countries, reporting 6.6 million cases and 6,200 deaths. We report the long-term entomological and epidemiological effectiveness of city-wide deployment of w Mel-strain Wolbachia -infected Aedes aegypti in Niterói, a city of half a million people in Rio de Janeiro state, where Wolbachia releases across 70% of the urban population in 2017-2019 were expanded to remaining populated areas in 2023. w Mel was durably established at ≥95% prevalence in Ae. aegypti populations throughout Niterói four years post-release, and up to seven years in the earliest release sites. This city-wide Wolbachia coverage provided sustained population-level protection against dengue throughout the five years post-intervention, including during the 2024 epidemic surge, averting an estimated three-quarters of the dengue case burden that would otherwise have been expected in Niterói in 2024.