Exploiting Intimate Relationships: Controlling Mosquito-Transmitted Disease with Wolbachia

Mosquito-transmitted diseases impose a growing burden on human health, and current control strategies have proven insufficient to stem the tide. The bacterium Wolbachia is a novel and promising form of control for mosquito-transmitted disease. It manipulates host biology, restricts infection with dengue and other pathogens, and alters host reproduction to promote rapid spread in the field. In this review, we examine how the intimate and diverse relationships formed between Wolbachia and their mosquito hosts can be exploited for disease control purposes. We consider these relationships in the context of recent developments, including successful field trials with Wolbachia-infected mosquitoes to combat dengue, and new Wolbachia infections in key malaria vectors, which have enhanced the disease control prospects of this unique bacterium.

TrendsWolbachia-infected Aedes aegypti mosquitoes have been successfully released in the field. The Wolbachia infection and desirable host manipulations are stable, and strong inhibition of dengue still occurs after more than 2 years of field exposure.Researchers have identified several changes to host biology linked to pathogen interference, including increases in immune gene expression and reactive oxygen species levels; however, different combinations of these changes have been associated with pathogen interference in different species, leaving the cause of the phenotype unclear.Some Wolbachia strains can enhance infection with certain pathogens, but there is no evidence of this occurring for dengue or human malaria. Enhancement has not been observed in the stable Wolbachia–mosquito associations being considered for disease control purposes.The application of Wolbachia for malaria control is advancing rapidly, with the identification of a native infection in Anopheles gambiae, and the creation of the first stable transinfection in Anopheles stephensi, which inhibits infection with the human malaria parasite Plasmodium falciparum.