Quantifying the impact of Wolbachia releases on dengue infection in Townsville, Australia

Abstract

From October 2014 to February 2019, local authorities in Townsville, North Queensland, Australia continually introduced Wolbachia-infected mosquitoes to control seasonal outbreaks of dengue infection. In this study, we develop a mathematical modelling framework to estimate the effectiveness of this intervention as well as the relative dengue transmission rates of Wolbachia-infected and wild-type mosquitoes. We find that the transmission rate of Wolbachia-infected mosquitoes is reduced approximately by a factor of 20 relative to the uninfected wild-type population. In addition, the Townsville Wolbachia release program led to a 65% reduction in predicted dengue incidence during the release period and over 95% reduction in the 24 months that followed. Finally, to investigate the potential impact of other Wolbachia release programs, we use our estimates of relative transmissibility to calculate the relationship between the reproductive number of dengue and the proportion of Wolbachia-infected mosquitoes in the vector population.

Genetic and geographic population structure in the malaria vector, Anopheles farauti, provides a candidate system for pioneering confinable gene-drive releases

“…As well as this, releasing in a first world and geographically isolated country such as Australia, permits the identification of any potential risks and may facilitate better building of public trust in the technology prior to it being taken to developing countries. A similar release model was implemented and shown to be effective with the initial release and subsequent population replacement of Wolbachia infected Aedes aegypti in north Queensland (Hoffmann et al 2011 ; Ogunlade et al 2023 ). These populations have persisted to this day and remain effective in mitigating Dengue risk in the region (Ross et al 2022 ; Ogunlade et al 2023 ).…”

“…A similar release model was implemented and shown to be effective with the initial release and subsequent population replacement of Wolbachia infected Aedes aegypti in north Queensland (Hoffmann et al 2011 ; Ogunlade et al 2023 ). These populations have persisted to this day and remain effective in mitigating Dengue risk in the region (Ross et al 2022 ; Ogunlade et al 2023 ).…”

Introduction of invasive mosquito species into Europe and prospects for arbovirus transmission and vector control in an era of globalization

“…The Wolbachia release program in Townsville, Australia, led to a 65% reduction in predicted DENV incidence during the release period and over 95% reduction in the 24 months that followed [ 131 ]. The release of males of Ae.…”

Dengue: A review of laboratory diagnostics in the vaccine age

“…Control and mitigation measures for DENV may impact the need for laboratory diagnostics. Control measures have had some recent successes, including the deployment of Wolbachia-infected mosquitos (which has significantly decreased infection rates in release areas) [17][18][19][20][21][22][23], and the development of vaccines [24][25][26][27]. Due to the risk of subsequent severe DENV infection related to ADE [28], vaccination is only recommended for those who have confirmed prior DENV infection, unless there is high local seroprevalence in the target age group for vaccination [27,29].…”