Mosquitos are the banes of our existence — they suck our blood, they spread disease, and for that, they suck in general. Some viruses that mosquitoes, such as the dengue viruses, can be debilitating or even lethal. Scientists have previously shown that infecting mosquitoes with the insect-specific bacterium, Wolbachia pipientis, can stop or slow the replication of dengue virus within the bugs. That work raised the question: Can Wolbachia-infected mosquitoes help prevent the spread of dengue?

In a new study published in The New England Journal of Medicine, researchers sought to answer this question by releasing Aedes aegypti mosquitoes (the type that transmits dengue) with or without Wolbachia into geographic clusters throughout Yogyakarta, Indonesia. They found that Wolbachia-infected mosquitoes maintained stable populations in their areas of release over the three-year experiment. Importantly, the incidence of dengue fever was significantly lower among people living in clusters with Wolbachia-positive mosquitos relative to control clusters — 2.3 percent and 9.3 percent, respectively. 

This study points to the efficacy of Wolbachia-mediated methods for controlling dengue virus, and potentially other diseases like yellow fever and Zika. Given the Wolbachia method is being deployed in various regions throughout the world, this new work bolsters evidence that bacteria may be the key for keeping mosquito-transmitted viruses in check.