Establishment of wMel Wolbachia in Aedes aegypti mosquitoes and reduction of local dengue transmission in Cairns and surrounding locations in northern Queensland, Australia [version 2; peer review: 2 approved]

Peter A. Ryan; Andrew P. Turley; Geoff Wilson; Tim P. Hurst; Kate Retzki; Jack Brown-Kenyon; Lauren Hodgson; Nichola Kenny; Helen Cook; Brian L. Montgomery; Christopher J. Paton; Scott A. Ritchie; Ary A. Hoffmann; Nicholas P. Jewell; Stephanie K. Tanamas; Katherine L. Anders; Cameron P. Simmons; Scott L. O’Neill

doi:10.12688/gatesopenres.13061.2

Gates Open Research (Apr 2020)

Establishment of wMel Wolbachia in Aedes aegypti mosquitoes and reduction of local dengue transmission in Cairns and surrounding locations in northern Queensland, Australia [version 2; peer review: 2 approved]

Peter A. Ryan,
Andrew P. Turley,
Geoff Wilson,
Tim P. Hurst,
Kate Retzki,
Jack Brown-Kenyon,
Lauren Hodgson,
Nichola Kenny,
Helen Cook,
Brian L. Montgomery,
Christopher J. Paton,
Scott A. Ritchie,
Ary A. Hoffmann,
Nicholas P. Jewell,
Stephanie K. Tanamas,
Katherine L. Anders,
Cameron P. Simmons,
Scott L. O’Neill

Affiliations

Peter A. Ryan: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Andrew P. Turley: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Geoff Wilson: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Tim P. Hurst: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Kate Retzki: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Jack Brown-Kenyon: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Lauren Hodgson: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Nichola Kenny: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Helen Cook: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Brian L. Montgomery: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Christopher J. Paton: College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland, Australia
Scott A. Ritchie: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Ary A. Hoffmann: School of Biosciences, Bio21 Institute, University of Melbourne, Parkville, Victoria, Australia
Nicholas P. Jewell: Division of Epidemiology and Biostatistics, School of Public Health, University of California, Berkeley, California, USA
Stephanie K. Tanamas: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Katherine L. Anders: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Cameron P. Simmons: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia
Scott L. O’Neill: Institute of Vector-Borne Disease, Monash University, Clayton, Victoria, 3800, Australia

DOI: https://doi.org/10.12688/gatesopenres.13061.2
Journal volume & issue: Vol. 3

Abstract

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Background: The wMel strain of Wolbachia has been successfully introduced into Aedes aegypti mosquitoes and subsequently shown in laboratory studies to reduce transmission of a range of viruses including dengue, Zika, chikungunya, yellow fever, and Mayaro viruses that cause human disease. Here we report the entomological and epidemiological outcomes of staged deployment of Wolbachia across nearly all significant dengue transmission risk areas in Australia. Methods: The wMel strain of Wolbachia was backcrossed into the local Aedes aegypti genotype (Cairns and Townsville backgrounds) and mosquitoes were released in the field by staff or via community assisted methods. Mosquito monitoring was undertaken and mosquitoes were screened for the presence of Wolbachia. Dengue case notifications were used to track dengue incidence in each location before and after releases. Results: Empirical analyses of the Wolbachia mosquito releases, including data on the density, frequency and duration of Wolbachia mosquito releases, indicate that Wolbachia can be readily established in local mosquito populations, using a variety of deployment options and over short release durations (mean release period 11 weeks, range 2-22 weeks). Importantly, Wolbachia frequencies have remained stable in mosquito populations since releases for up to 8 years. Analysis of dengue case notifications data demonstrates near-elimination of local dengue transmission for the past five years in locations where Wolbachia has been established. The regression model estimate of Wolbachia intervention effect from interrupted time series analyses of case notifications data prior to and after releases, indicated a 96% reduction in dengue incidence in Wolbachia treated populations (95% confidence interval: 84 – 99%). Conclusion: Deployment of the wMel strain of Wolbachia into local Ae. aegypti populations across the Australian regional cities of Cairns and most smaller regional communities with a past history of dengue has resulted in the reduction of local dengue transmission across all deployment areas.

Published in Gates Open Research

ISSN: 2572-4754 (Online)
Publisher: F1000 Research Ltd
Country of publisher: United Kingdom
LCC subjects: Medicine
Website: https://gatesopenresearch.org/

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