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

Traditional methods of vector control have proven insufficient to reduce the alarming incidence of dengue, Zika, and chikungunya in endemic countries. The bacterium symbiont Wolbachia has emerged as an efficient pathogen-blocking and self-dispersing agent that reduces the vectorial potential of Aedes aegypti populations and potentially impairs arboviral disease transmission. In this work, we report the results of a large-scale Wolbachia intervention in Ilha do Governador, Rio de Janeiro, Brazil. wMel-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 wMel prevalence in field specimens and analyzed introgression profiles of two assigned intervention areas, RJ1 and RJ2. Our results revealed that wMel 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, wMel 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 (r = 0.2849, p = 0.0236), and an association at a higher degree when comparing different deployment strategies, vehicle or backpack-assisted, within RJ1 (r = 0.4676, p < 0.0001) or RJ2 (r = 0.6263, p < 0.0001). The frequency knockdown resistance (kdr) alleles in wMel-infected specimens from both areas were consistently high over this study. Altogether, these findings corroborate that wMel 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.

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Large-scale deployment and establishment of Wolbachia into the Aedes aegypti population in Rio de Janeiro, Brazil.

10.1101/2021.04.29.441982 ◽

2021 ◽

Author(s):

Joao Silveira Moledo Gesto ◽

Sofia Pinto ◽

Fernando Braga Stehling Dias ◽

Julia Peixoto ◽

Guilherme Costa ◽

...

Keyword(s):

Aedes Aegypti ◽

Vector Control ◽

Disease Transmission ◽

Rio De Janeiro ◽

Large Scale ◽

Southeastern Brazil ◽

Infection Rates ◽

Residential Areas ◽

Dispersing Agent ◽

Vector Control Intervention

Traditional methods of vector control have proven insufficient to reduce the alarming incidence of Dengue, Zika and chikungunya in endemic countries. The bacterium symbiont Wolbachia has emerged as an efficient pathogen-blocking and self-dispersing agent that reduces the vectorial potential of Aedes aegypti populations and potentially impairs arboviral disease transmission. In this work, we report the results of a large-scale Wolbachia intervention in Ilha do Governador, Rio de Janeiro, Brazil. wMel-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 wMel prevalence in field specimens, and analyzed introgression profiles of two assigned intervention areas, RJ1 and RJ2. Our results revealed that wMel 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, wMel 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 (r = 0.2849, P = 0.0236), and an association at a higher degree when comparing different deployment strategies, vehicle or backpack-assisted, within RJ1 (r = 0.4676, P < 0.0001) or RJ2 (r = 0.6263, P < 0.0001). The frequency knockdown resistance (kdr) alleles in wMel-infected specimens from both areas was consistently high over this study. Altogether, these findings corroborate that wMel 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.

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The impact of large-scale deployment of Wolbachia mosquitoes on arboviral disease incidence in Rio de Janeiro and Niterói, Brazil: study protocol for a controlled interrupted time series analysis using routine disease surveillance data

F1000Research ◽

10.12688/f1000research.19859.1 ◽

2019 ◽

Vol 8 ◽

pp. 1328

Author(s):

Betina Durovni ◽

Valeria Saraceni ◽

Ana Eppinghaus ◽

Thais I.S. Riback ◽

Luciano A. Moreira ◽

...

Keyword(s):

Time Series ◽

Time Series Analysis ◽

Vector Control ◽

Study Protocol ◽

Disease Surveillance ◽

Rio De Janeiro ◽

Large Scale ◽

Interrupted Time Series ◽

Interrupted Time Series Analysis ◽

Arboviral Disease

Background: Rio de Janeiro and Niterói municipalities in southeastern Brazil experience large dengue epidemics every 2 to 5 years, with >100,000 cases notified in epidemic years. Costs of vector control and direct and indirect costs due to the Aedes-borne diseases dengue, chikungunya and Zika were estimated to total $650 million USD in 2016, but traditional vector control strategies have not been effective in preventing arboviral disease outbreaks. The Wolbachia method is a novel and self-sustaining approach for the biological control of arboviral diseases, in which the transmission potential of Ae. aegypti mosquitoes is reduced by stably transfecting them with the Wolbachia bacterium. This paper describes a study protocol for evaluating the effect of large-scale non-randomised releases of Wolbachia mosquitoes on the incidence of dengue, Zika and chikungunya in the municipalities of Niterói and Rio de Janeiro. This follows a lead-in period since 2014 involving intensive community engagement, regulatory and public approval, entomological surveys, and small-scale pilot releases. Method: The planned releases during 2017-2019 cover a combined area of 121 km2 with a resident population of 1.1 million, across the two cities. Untreated areas with comparable historical dengue profiles and sociodemographic characteristics have been identified a priori as comparative control areas in each municipality. The proposed pragmatic epidemiological approach combines a controlled interrupted time series analysis of routinely notified suspected and laboratory-confirmed arboviral cases, together with monitoring of arbovirus activity utilising outbreak signals routinely used in public health disease surveillance. Discussion: If the current project is successful, this model for control of arboviral disease through Wolbachia releases can be expanded nationally and regionally.

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Insecticide resistance and genetic structure of Aedes aegypti populations from Rio de Janeiro State, Brazil

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0008492 ◽

2021 ◽

Vol 15 (2) ◽

pp. e0008492 ◽

Cited By ~ 1

Author(s):

Rafi Ur Rahman ◽

Luciano Veiga Cosme ◽

Monique Melo Costa ◽

Luana Carrara ◽

José Bento Pereira Lima ◽

...

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Aedes Aegypti ◽

Insecticide Resistance ◽

Vector Control ◽

Rio De Janeiro ◽

Control Program ◽

Positive Control ◽

World Health ◽

Janeiro State

Vector control largely relies on neurotoxic chemicals, and insecticide resistance (IR) directly threatens their effectiveness. In some cases, specific alleles cause IR, and knowledge of the genetic diversity and gene flow among mosquito populations is crucial to track their arrival, rise, and spread. Here we evaluated Aedes aegypti populations’ susceptibility status, collected in 2016 from six different municipalities of Rio de Janeiro state (RJ), to temephos, pyriproxyfen, malathion, and deltamethrin. We collected eggs of Ae. aegypti in Campos dos Goytacazes (Cgy), Itaperuna (Ipn), Iguaba Grande (Igg), Itaboraí (Ibr), Mangaratiba (Mgr), and Vassouras (Vsr). We followed the World Health Organization (WHO) guidelines and investigated the degree of susceptibility/resistance of mosquitoes to these insecticides. We used the Rockefeller strain as a susceptible positive control. We genotyped the V1016I and F1534C knockdown resistance (kdr) alleles using qPCR TaqMan SNP genotyping assay. Besides, with the use of Ae. aegypti SNP-chip, we performed genomic population analyses by genotyping more than 15,000 biallelic SNPs in mosquitoes from each population. We added previous data from populations from other countries to evaluate the ancestry of RJ populations. All RJ Ae. aegypti populations were susceptible to pyriproxyfen and malathion and highly resistant to deltamethrin. The resistance ratios for temephos was below 3,0 in Cgy, Ibr, and Igg populations, representing the lowest rates since IR monitoring started in this Brazilian region. We found the kdr alleles in high frequencies in all populations, partially justifying the observed resistance to pyrethroid. Population genetics analysis showed that Ae. aegypti revealed potential higher migration among some RJ localities and low genetic structure for most of them. Future population genetic studies, together with IR data in Ae aegypti on a broader scale, can help us predict the gene flow within and among the Brazilian States, allowing us to track the dynamics of arrival and changes in the frequency of IR alleles, and providing critical information to improving vector control program.

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Efficacy of Aedes aegypti control by indoor Ultra Low Volume (ULV) insecticide spraying in Iquitos, Peru

10.1101/231134 ◽

2017 ◽

Author(s):

Christian Gunning ◽

Kenichi Okamoto ◽

Helvio Astete ◽

Gissella M. Vasquez ◽

Erik Erhardt ◽

...

Keyword(s):

Aedes Aegypti ◽

Disease Transmission ◽

Large Scale ◽

Baseline Survey ◽

Pyrethroid Insecticides ◽

Young Females ◽

Primary Vector ◽

The Mean ◽

Low Volume ◽

Epidemiological Impact

ABSTRACTBackgroundAedes aegypti is a primary vector of dengue, chikungunya, Zika, and urban yellow fever viruses. Indoor, ultra low volume (ULV) space spraying with pyrethroid insecticides is the main approach used for Ae. aegypti emergency control in many countries. Given the widespread use of this method, the lack of large-scale experiments or detailed evaluations of municipal spray programs is problematic.Methodology/Principal FindingsTwo experimental evaluations of non-residual, indoor ULV pyrethroid spraying were conducted in Iquitos, Peru. In each, a central sprayed sector was surrounded by an unsprayed buffer sector. In 2013, spray and buffer sectors included 398 and 765 houses, respectively. Spraying reduced the mean number of adults captured per house by ~83 percent relative to the pre-spray baseline survey. In the 2014 experiment, sprayed and buffer sectors included 1,117 and 1,049 houses, respectively. Here, the sprayed sector’s number of adults per house was reduced ~64 percent relative to baseline. Parity surveys in the sprayed sector during the 2014 spray period indicated an increase in the proportion of very young females. We also evaluated impacts of a 2014 citywide spray program by the local Ministry of Health, which reduced adult populations by ~60 percent. In all cases, adult densities returned to near-baseline levels within one month.Conclusions/SignificanceOur results demonstrate that densities of adult Ae. aegypti can be reduced by experimental and municipal spraying programs. The finding that adult densities return to approximately pre-spray densities in less than a month is similar to results from previous, smaller scale experiments. Our results demonstrate that ULV spraying is best viewed as having a short-term entomological effect. The epidemiological impact of ULV spraying will need evaluation in future trials that measure capacity of insecticide spraying to reduce disease transmission.

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Reduced competence to arboviruses following the sustainable invasion of Wolbachia into native Aedes aegypti from Southeastern Brazil

Scientific Reports ◽

10.1038/s41598-021-89409-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

João Silveira Moledo Gesto ◽

Gabriel Sylvestre Ribeiro ◽

Marcele Neves Rocha ◽

Fernando Braga Stehling Dias ◽

Julia Peixoto ◽

...

Keyword(s):

Aedes Aegypti ◽

Disease Transmission ◽

Oral Feeding ◽

Southeastern Brazil ◽

Proof Of Concept ◽

Small Community ◽

High Infection ◽

Promising Solution ◽

Virus Blocking

AbstractField release of Wolbachia-infected Aedes aegypti has emerged as a promising solution to manage the transmission of dengue, Zika and chikungunya in endemic areas across the globe. Through an efficient self-dispersing mechanism, and the ability to induce virus-blocking properties, Wolbachia offers an unmatched potential to gradually modify wild Ae. aegypti populations turning them unsuitable disease vectors. Here we describe a proof-of-concept field trial carried out in a small community of Niterói, greater Rio de Janeiro, Brazil. Following the release of Wolbachia-infected eggs, we report here a successful invasion and long-term establishment of the bacterium across the territory, as denoted by stable high-infection indexes (> 80%). We have also demonstrated that refractoriness to dengue and Zika viruses, either thorough oral-feeding or intra-thoracic saliva challenging assays, was maintained over the adaptation to the natural environment of Southeastern Brazil. These findings further support Wolbachia’s ability to invade local Ae. aegypti populations and impair disease transmission, and will pave the way for future epidemiological and economic impact assessments.

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Reduced competence to arboviruses following the sustainable invasion of Wolbachia into native Aedes aegypti from Niterói, Southeastern Brazil

10.1101/2020.09.25.312207 ◽

2020 ◽

Cited By ~ 1

Author(s):

João Silveira Moledo Gesto ◽

Gabriel Sylvestre Ribeiro ◽

Marcele Neves Rocha ◽

Fernando Braga Stehling Dias ◽

Julia Peixoto ◽

...

Keyword(s):

Aedes Aegypti ◽

Disease Transmission ◽

Oral Feeding ◽

Southeastern Brazil ◽

Proof Of Concept ◽

Small Community ◽

High Infection ◽

Promising Solution ◽

Virus Blocking

AbstractField release of Wolbachia-infected Aedes aegypti has emerged as a promising solution to manage the transmission of dengue, Zika and chikungunya in endemic areas across the globe. Through an efficient self-dispersing mechanism, and the ability to induce virus-blocking properties, Wolbachia offers an unmatched potential to gradually modify wild Ae. aegypti populations turning them unsuitable disease vectors. Here in this work, a proof-of-concept field trial was carried out in a small community of Niterói, greater Rio de Janeiro. Following the release of Wolbachia-infected eggs, we reported a successful invasion and long-term establishment of the bacterium across the territory, as denoted by stable high-infection indexes (>80%). We have also demonstrated that refractoriness to dengue and Zika viruses, either thorough oral-feeding or intra-thoracic saliva challenging assays, were maintained over the adaptation to the natural environment of Southeastern Brazil. These findings further support Wolbachia’s ability to invade local Ae. aegypti populations and impair disease transmission, and shall pave the way for future epidemiological and economic impact assessments.

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PENGENDALIAN VEKTOR NYAMUK AEDES AEGYPTI DI RUMAH SAKIT KOTA SURABAYA

The Indonesian Journal of Public Health ◽

10.20473/ijph.v13i1.2018.73-84 ◽

2019 ◽

Vol 13 (1) ◽

pp. 73

Author(s):

Ekalina Atikasari ◽

Lilis Sulistyorini

Keyword(s):

Aedes Aegypti ◽

Vector Control ◽

Environmental Health ◽

Disease Transmission ◽

Mosquito Control ◽

Secondary Data ◽

Mosquito Vector ◽

Human Contact ◽

The Republic ◽

And Control

Vector control is an approach using the basic principles of management and consideration of disease transmission and control. The purpose of vector control is to reduce vector breeding habitats, reduce vector density, inhibit disease transmission, reduce human contact with vectors so that vector-borne disease transmission can be controlled more rationally, effectively and efficiently. This study aims to analyze the effectiveness of Aedes aegypti mosquito control vector in a hospital in Surabaya. The Control carried out by the Hospital is to eradicate Aedes aegypti mosquitoes by installing Ovitrap, Thermal Fogging, Cold Fogging and Spraying. The type of analysis used is descriptive observational. Data collection was carried out in February of 2017 at K3 unit and Environmental Health of Surabaya Hospital. The data used are hospital pest and rodent control report, secondary data aboutnumber of mosquito, number of larvae and number of Aedes aegypti mosquito eggs obtained from unit of K3 and Environmental Health. The conclusions for the hospital are: (1) always report the Aedes aegypti mosquito vector routine every months; (2) eradicating mosquitoes in difficult places such as patient and dense populated areas; (3) based on Regulation of the Minister of Health of the Republic of Indonesia Number 374 / MENKES / PER / III / 2010 concerning Vector Control four of the six tools used in the Hospital have been used

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The impact of large-scale deployment of Wolbachia mosquitoes on dengue and other Aedes-borne diseases in Rio de Janeiro and Niterói, Brazil: study protocol for a controlled interrupted time series analysis using routine disease surveillance data

F1000Research ◽

10.12688/f1000research.19859.2 ◽

2020 ◽

Vol 8 ◽

pp. 1328

Author(s):

Betina Durovni ◽

Valeria Saraceni ◽

Ana Eppinghaus ◽

Thais I.S. Riback ◽

Luciano A. Moreira ◽

...

Keyword(s):

Time Series ◽

Time Series Analysis ◽

Vector Control ◽

Study Protocol ◽

Disease Surveillance ◽

Rio De Janeiro ◽

Large Scale ◽

Interrupted Time Series ◽

Interrupted Time Series Analysis ◽

Series Analysis

Background: Rio de Janeiro and Niterói are neighbouring cities in southeastern Brazil which experience large dengue epidemics every 2 to 5 years, with >100,000 cases notified in epidemic years. Costs of vector control and direct and indirect costs due to the Aedes-borne diseases dengue, chikungunya and Zika were estimated to total $650 million USD in 2016, but traditional vector control strategies have not been effective in preventing mosquito-borne disease outbreaks. The Wolbachia method is a novel and self-sustaining approach for the biological control of Aedes-borne diseases, in which the transmission potential of Aedes aegypti mosquitoes is reduced by stably transfecting them with the Wolbachia bacterium (wMel strain). This paper describes a study protocol for evaluating the effect of large-scale non-randomised releases of Wolbachia-infected mosquitoes on the incidence of dengue, Zika and chikungunya in the two cities of Niterói and Rio de Janeiro. This follows a lead-in period since 2014 involving intensive community engagement, regulatory and public approval, entomological surveys, and small-scale pilot releases. Method: The Wolbachia releases during 2017-2019 covered a combined area of 170 km2 with a resident population of 1.2 million, across Niterói and Rio de Janeiro. Untreated areas with comparable historical dengue profiles and demographic characteristics have been identified a priori as comparative control areas in each city. The proposed pragmatic epidemiological approach combines a controlled interrupted time series analysis of routinely notified suspected and laboratory-confirmed dengue and chikungunya cases, together with monitoring of Aedes-borne disease activity utilising outbreak signals routinely used in public health disease surveillance. Discussion: If the current project is successful, this model for control of mosquito-borne disease through Wolbachia releases can be expanded nationally and regionally.

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How to engage communities on a large scale? Lessons from World Mosquito Program in Rio de Janeiro, Brazil

Gates Open Research ◽

10.12688/gatesopenres.13153.2 ◽

2021 ◽

Vol 4 ◽

pp. 109

Author(s):

Guilherme B. Costa ◽

Ruth Smithyman ◽

Scott L. O'Neill ◽

Luciano A. Moreira

Keyword(s):

Community Engagement ◽

Vector Control ◽

Rio De Janeiro ◽

Large Scale ◽

Local Development ◽

World Health ◽

Integrated Analysis ◽

Novel Technologies ◽

The World ◽

Global Vector

One of the pillars of the World Health Organization’s (WHO) Global Vector Control Response 2017–2030 strategy is the engagement of communities. Among the priority activities, defined by 2022 by the WHO, is the development of plans for the effective engagement and mobilisation of communities in vector control. Novel technologies for arboviruses control are being developed, such as the Wolbachia method, implemented by the World Mosquito Program (WMP). Here we discuss and analyse the framework for community engagement implemented by the WMP in Brazil, during the large-scale deployment of the method in the municipalities of Niterói and Rio de Janeiro, Brazil. Our experience indicates that the community engagement work for arboviruses control should be understood as an opportunity for local development. It is necessary, based on an integrated analysis of the territory, to understand that the actions for arboviruses control could be a catalyst for the necessary socioenvironmental, cultural and public health changes. Furthermore, it is essential to understand that community engagement goes beyond informing or asking for population consent, but it constitutes a possibility for dialogue and exchange between the various stakeholders present in the territories, to build on cooperation for mosquito-borne disease control.

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