Projects per year
Abstract
Background The introduction of Wolbachia (wMel strain) into Aedes aegypti mosquitoes reduces their capacity to transmit dengue and other arboviruses. Randomised and non-randomised studies in multiple countries have shown significant reductions in dengue incidence following field releases of wMel-infected Ae. aegypti. We report the public health outcomes from phased, large-scale releases of wMel-Ae. aegypti mosquitoes throughout three contiguous cities in the Aburrá Valley, Colombia. Methodology/Principal findings Following pilot releases in 2015–2016, staged city-wide wMel-Ae. aegypti deployments were undertaken in the cities of Bello, Medellín and Itagüí (3.3 million people) between Octo-ber 2016 and April 2022. The impact of the Wolbachia intervention on dengue incidence was evaluated in two parallel studies. A quasi-experimental study using interrupted time series analysis showed notified dengue case incidence was reduced by 95% in Bello and Medellín and 97% in Itagüí, following establishment of wMel at 60% prevalence, compared to the pre-intervention period and after adjusting for seasonal trends. A concurrent clinic-based case-control study with a test-negative design was unable to attain the target sample size of 63 enrolled virologically-confirmed dengue (VCD) cases between May 2019 and December 2021, consistent with low dengue incidence throughout the Aburrá Valley following wMel deployments. Nevertheless, VCD incidence was 45% lower (OR 0.55 [95% CI 0.25, 1.17]) and combined VCD/presumptive dengue incidence was 47% lower (OR 0.53 [95% CI 0.30, 0.93]) among participants resident in wMel-treated versus untreated neighbourhoods. Conclusions/Significance Stable introduction of wMel into local Ae. aegypti populations was associated with a significant and sustained reduction in dengue incidence across three Colombian cities. These results from the largest contiguous Wolbachia releases to-date demonstrate the real-world effectiveness of the method across large urban populations and, alongside previously published results, support the reproducibility of this effectiveness across different ecological settings.
Original language | English |
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Article number | e0011713 |
Number of pages | 20 |
Journal | PLoS Neglected Tropical Diseases |
Volume | 17 |
Issue number | 11 |
DOIs | |
Publication status | Published - Nov 2023 |
Projects
- 2 Finished
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Large scale deployment of Wolbachia across diverse urban communities in Rio de Janeiro and Niterói and development of a pilot model for national roll-out.
O'Neill, S.
23/11/16 → 30/11/18
Project: Research
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Pilot deployment of Wolbachia technology to reduce transmission of Aedes aegypti-borne diseases, including Zika, dengue and chikungunya in Medellin, Colombia.
O'Neill, S.
United States Agency for International Development (USAID), Wellcome Trust, Bill and Melinda Gates Foundation
3/10/16 → 31/12/22
Project: Research