Wolbachia used to counter dengue fever

The mosquito-borne viral disease dengue fever is an increasing problem in tropical and subtropical regions. Traditional control measures aimed at reducing populations of the main transmission vector, Aedes aegypti, have had little success. Two papers in this issue report an alternative approach to mosquito population control using the bacterium Wolbachia pipientis, natural insect symbionts that facilitate their own transmission through a process called cytoplasmic incompatibility. In the first paper, Scott O'Neill and colleagues describe a Wolbachia strain derived from fruitflies that significantly reduces dengue virus carriage in mosquitoes without imposing a fitness cost. In the second paper, they demonstrate in a controlled field trial that the release of colonized mosquitoes leads to successful invasion of natural mosquito populations. These results suggest a viable strategy to control dengue fever.