Mathematical Modelling to Investigate a Wolbachia Intervention to Reduce Dengue Transmission

The introduction of Wolbachia-carrying mosquitoes into the population has recently been proposed as an alternative strategy against dengue. Although laboratory experiments have shown that the Wolbachia bacterium can reduce the levels of dengue virus in mosquitoes, it is also important to assess the performance of Wolbachia in reducing the incidence of dengue in human populations. In this thesis, deterministic mathematical models of human and mosquito populations in which either one or two dengue serotypes circulate are developed. We adapt these models to enable the investigation of dengue disease dynamics in the absence and presence of Wolbachia in order to assess the performance of Wolbachia as a strategy to reduce human dengue incidence. When studying the situation in which a single dengue serotype is present in the population, we consider scenarios where dengue is introduced into the human population once and multiple times. We find that when mosquitoes infected with the Wolbachia strain WMel, which reduces the mosquito lifespan by at most 10%, are released into the population, the Wolbachia-carrying mosquitoes persist. The ranges of the reproductive and death rates for Wolbachia-carrying mosquitoes which allow mosquitoes carrying Wolbachia to persist in competition with non-Wolbachia carrying mosquitoes are also found. Furthermore, the transmission probability, the biting rate and the average death rate are the parameters exerting the most influence on the cumulative number of infectious individuals in the population. An analysis of the basic reproduction number, R0, for the model consider-