Efficacy of Wolbachia-Infected Mosquito Deployments for the Control of Dengue

Abstract

Background: Aedes aegypti mosquitoes infected with Wolbachia pipientis ( w Mel strain) have reduced potential to transmit dengue viruses. Methods: We conducted a cluster randomised trial of deployments of w Mel-infected Ae. aegypti for control of dengue in Yogyakarta City, Indonesia. Twenty-four geographic clusters were randomly allocated to receive w Mel deployments as an adjunct to local mosquito control measures; or to continue with local mosquito control measures only. A test-negative design was used to measure efficacy. Study participants were persons 3–45 years old attending primary care clinics with acute undifferentiated fever. Laboratory testing identified virologically-confirmed dengue cases and test-negative controls. The primary endpoint was efficacy of w Mel in reducing the incidence of symptomatic, virologically-confirmed dengue, caused by any dengue virus serotype. Results: Following successful introgression of w Mel in intervention clusters, 8144 participants were enrolled; 3721 from w Mel-treated clusters and 4423 from untreated clusters. In the ITT analysis virologically-confirmed dengue occurred in 67 of 2905 (2.3%) participants in the w Mel-treated and 318 of 3401 (9.4%) in the untreated arm (OR 0.23, 95% CI, 0.15 to 0.35; P=0.004): protective efficacy of 77.1% (95% CI, 65.3 to 84.9). Protective efficacy was similar for the four serotypes. Hospitalisation for virologically-confirmed dengue was less frequent for participants resident in the w Mel-treated (13/2905, 2.8%) compared to the untreated arm (102/3401, 6.3%): protective efficacy 86.2% (95% CI, 66.2 to 94.3) Conclusions: w Mel introgression into Ae. aegypti populations was efficacious in reducing the incidence of symptomatic dengue, and also led to fewer dengue hospitalisations. Trial registration number: ClinicalTrials.gov Identifier: NCT03055585 and INA-A7OB6TW

Effectiveness of Wolbachia-infected mosquito deployments in reducing the incidence of dengue and other Aedes-borne diseases in Niterói, Brazil: A quasi-experimental study

“…Results from a recent cluster randomised trial of wMel-infected Ae aegypti deployments in Yogyakarta Indonesia demonstrated 77% efficacy in preventing virologically confirmed dengue cases [18], with comparable efficacy against all four dengue virus serotypes. Previous nonrandomised controlled field trials in Indonesia [15] and northern Australia [16,17] demonstrated 76% and 96% effectiveness, respectively, in reducing the incidence of dengue cases notified to routine disease surveillance systems.…”

“…aegypti populations [15][16][17]. A recently completed cluster randomised trial of wMel Wolbachia deployments in Yogyakarta, Indonesia, conclusively demonstrated the efficacy of the method, with a 77% reduction in dengue incidence in Wolbachia-treated neighbourhoods compared to untreated areas [18]. The Yogyakarta CRT included chikungunya and Zika as secondary endpoints, but insufficient cases were detected to permit an evaluation of efficacy against these arboviruses.…”

Mosquito Control Priorities in Florida—Survey Results from Florida Mosquito Control Districts

“…Over the past decade, several next generation mosquito control strategies have been tested in nature, with a view to supplementing or even replacing the types of interventions typically conducted by mosquito control districts. These new approaches include the use of the bacteria Wolbachia , which can be deployed at the city level to immunize mosquito populations against pathogens such as DENV [ 76 ]. Similarly, the Florida Keys Mosquito Control District has been working in collaboration with Oxitec to implement a novel genetics-based control strategy targeted at Ae.…”

Sixty seconds on . . . dengue

“…This is good news. A three year randomised controlled trial, published in the New England Journal of Medicine , showed that releasing mosquitoes infected with Wolbachia reduced the incidence of dengue fever by 77% and dengue hospital admissions by 86% 1…”