WOLBACHIA_MOD · The ecology and population dynamics of Wolbachia infections in Aedes aegypti and the development of new strategies for mosquito-borne disease control

An exciting new strategy for biocontrol of mosquito-borne diseases involves the endosymbiotic bacteria Wolbachia that infect several insect species. In the mosquito Aedes aegypti, the major vector of the dengue virus, infection with Wolbachia has been shown to greatly reduce the transmission of human pathogens including the dengue, yellow fever and chikungunya viruses. The Eliminate Dengue project, an international collaboration, is currently developing strategies for releasing Wolbachia into wild A. aegypti populations to render them incapable of transmitting these viruses. The operational success of this strategy relies on the rapid spread of Wolbachia through the mosquito vector population following their initial release. However, the spread of Wolbachia depends on two main factors. Firstly, Wolbachia incur a fitness cost on A. aegypti, which can prevent the bacteria from spreading, particularly if there is a strong fitness cost. In order to design release strategies that will achieve spread, we need to understand the fitness effects of Wolbachia on A. aegypti and how changing environmental conditions influences these effects. Secondly, Wolbachia needs to achieve a threshold prevalence in the mosquito population before it can spread which depends on the fitness cost caused by the bacteria. We need to understand the dynamics of Wolbachia infection in the mosquito population in order to predict release strategies that will allow a sufficiently high prevalence of Wolbachia to be maintained. This fellowship aims to advance our understanding of these ‘individual-level’ and ‘population-level’ processes that determine Wolbachia spread in A. aegypti in order to assist the design of Wolbachia release strategies to successfully drive Wolbachia through wild mosquito populations. An interdisciplinary investigation will develop a new data-driven mathematical modelling approach to predict Wolbachia dynamics under realistic conditions of environmental variability.