In 2016 we launched a ‘Quasi-experimental’ study in Yogyakarta, Indonesia to optimise methods for large-scale Wolbachia deployment and to evaluate the impact of our Wolbachia method on the incidence of dengue. Dengue is a huge problem in Indonesia, with millions of cases occurring each year.
Cameron Simmons is Director of Impact Assessment at WMP. “The success of earlier pilot Wolbachia releases coupled with endemic cycles of dengue made Yogyakarta an obvious location to pursue this pragmatic, quasi-experimental test of the public health utility of WMP’s method.”
To conduct the study, two locations were chosen on opposite sides of the city, which were comparable in sociodemographic characteristics and historical dengue incidence. In one of the areas, following extensive community engagement, Wolbachia-carrying mosquitoes were released every two weeks over seven months in 2016–17. The other ‘control’ area continued with routine dengue control measures.
Wolbachia was quickly and durably established in the mosquito population of the release area. We used data on the number of dengue cases reported to the Yogyakarta District Health Office from both release and control areas, to evaluate the impact of the Wolbachia deployments on dengue incidence.
The results were hugely encouraging. Dengue incidence decreased by 76 percent in the release area 30 months after the mosquito release, compared with the control area and with historical trends.
You can view the scientific paper on our quasi-experimental study here.
A gold-standard randomised controlled trial is ongoing in Yogyakarta with impact results due later this year. We look forward to sharing more good news!