AUTHOR=Gesto João Silveira Moledo , Pinto Sofia B. , Dias Fernando Braga Stehling , Peixoto Julia , Costa Guilherme , Kutcher Simon , Montgomery Jacqui , Green Benjamin R. , Anders Katherine L. , Ryan Peter A. , Simmons Cameron P. , O’Neill Scott L. , Moreira Luciano Andrade 

TITLE=Large-Scale Deployment and Establishment of Wolbachia Into the Aedes aegypti Population in Rio de Janeiro, Brazil

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.711107

DOI=10.3389/fmicb.2021.711107

ISSN=1664-302X

ABSTRACT=<p>Traditional methods of vector control have proven insufficient to reduce the alarming incidence of dengue, Zika, and chikungunya in endemic countries. The bacterium symbiont <italic>Wolbachia</italic> has emerged as an efficient pathogen-blocking and self-dispersing agent that reduces the vectorial potential of <italic>Aedes aegypti</italic> populations and potentially impairs arboviral disease transmission. In this work, we report the results of a large-scale <italic>Wolbachia</italic> intervention in Ilha do Governador, Rio de Janeiro, Brazil. <italic>w</italic>Mel-infected adults were released across residential areas between August 2017 and March 2020. Over 131 weeks, including release and post-release phases, we monitored the <italic>w</italic>Mel prevalence in field specimens and analyzed introgression profiles of two assigned intervention areas, RJ1 and RJ2. Our results revealed that <italic>w</italic>Mel successfully invaded both areas, reaching overall infection rates of 50–70% in RJ1 and 30–60% in RJ2 by the end of the monitoring period. At the neighborhood-level, <italic>w</italic>Mel introgression was heterogeneous in both RJ1 and RJ2, with some profiles sustaining a consistent increase in infection rates and others failing to elicit the same. Correlation analysis revealed a weak overall association between RJ1 and RJ2 (<italic>r</italic> = 0.2849, <italic>p</italic> = 0.0236), and an association at a higher degree when comparing different deployment strategies, vehicle or backpack-assisted, within RJ1 (<italic>r</italic> = 0.4676, <italic>p</italic> &lt; 0.0001) or RJ2 (<italic>r</italic> = 0.6263, <italic>p</italic> &lt; 0.0001). The frequency <italic>knockdown resistance</italic> (<italic>kdr</italic>) alleles in <italic>w</italic>Mel-infected specimens from both areas were consistently high over this study. Altogether, these findings corroborate that <italic>w</italic>Mel can be successfully deployed at large-scale as part of vector control intervention strategies and provide the basis for imminent disease impact studies in Southeastern Brazil.</p>