Plain English Summary
Background and study aims
Dengue is a viral infection spread by mosquitoes that is increasing in its global presence, with an estimated 4 billion people at risk of infection in at least 128 countries. Environmentally friendly approaches to mosquito control are needed to permanently reduce mosquito populations. The aim of this study is to find out whether an EcoHealth intervention based upon community mobilization reduces the risk of dengue virus infection among 3 to 9 years olds compared to usual dengue control practice in Fortaleza, Brazil.
Who can participate?
Households with children aged 3 to 9 years
What does the study involve?
Participating areas are randomly allocated to one of two groups. Household visits occur every six months for a total of six visits over a 3-year period to cover both dry and rainy seasons. In the intervention group areas community mobilization activities begin and locally customized activities are implemented. Customized community activities are developed during community meetings, lead by community members. Volunteers from the communities serve as organizers and educators trained by facilitators from the research team. Inter-community visits are organized to share experiences between communities and to strengthen the group dynamics and collective preventive action. The control group receive standard vector control in Fortaleza as determined by the Municipal Health Department of Fortaleza, which includes the application of temephos, a larvicide, in all water storage containers during outbreaks as well as insecticide spraying inside households and of the surrounding environment. Rates of dengue infection, exposure to mosquito bites, and the number of mosquito pupae are measured every 6 months over a 3-year period.
What are the possible benefits and risks of participating?
The results will help develop evidence-based mosquito control programs in Brazil and other countries struggling with mosquito-transmitted diseases. Importantly, this study will also provide estimates of dengue burden based upon a representative population sample, which is currently lacking in Brazil as they rely on passive surveillance. There is the potential risk of residents who fail to participate in community vector control activities being stigmatized, although based upon previous studies this risk is minimal. The researchers will monitor this risk throughout the study through community meetings and a reporting mechanism.
Where is the study run from?
Universidade Estadual do Ceara (Brazil)
When is the study starting and how long is it expected to run for?
October 2018 to March 2022
Who is funding the study?
Canadian Institutes of Health Research (Canada)
Who is the main contact?
Dr Kate Zinszer
Dr Kate Zinszer
School of Public Health
University of Montreal
7101 Park Ave
Improving Aedes control through community mobilization to reduce dengue incidence in Brazil: a cluster randomized controlled trial
The principal research question is: does community mobilization reduce the risk of dengue virus infection compared to usual dengue control practice in Fortaleza, Brazil.
Approval pending from the Health Research Ethics Board at the University of Montreal and the Ethics Committee at Ceará State University
Two-arm cluster randomized controlled trial
Primary study design
Secondary study design
Cluster randomised trial
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet.
The present study will follow a pragmatic cluster RCT design with randomization at the census tract level with equal allocation to the two arms. There will be 34 clusters in each arm of 80 children aged between 3 to 9 years old for a total of 5,440 children enrolled in the study.
Household visits will occur every six months for a total of six visits over a 3-year period to cover both dry and rainy seasons. At allocation, community mobilization activities will begin and locally customized activities will be implemented. Customized community activities will be developed during community meetings, lead by community members. There will be volunteers from the communities, who will serve as organizers and educators trained by facilitators from the research team. Inter-community visits will be organized to share experiences between communities and to strengthen the group dynamics and the collective preventive action.
The control group will receive standard vector control in Fortaleza as determined by the Municipal Health Department of Fortaleza, which includes the application of temephos, an organophosphate larvicide, in all water storage containers during outbreaks as well as insecticide spraying inside households and of the surrounding environment.
Baseline and follow-up findings will be presented individually during households visits and by cluster during community meetings to further engage households and community members. The duration of data collection is two years.
Primary outcome measure
Measured every 6 months over a 3-year period:
1. Rates of anti-dengue Immunoglobin G (IgG) seroconversion (from negative to positive at follow-up) to evaluate the incidence of primary infections, measured using enzyme-linked immunoabsorbent assays (ELISA)
2. Level of IgG to N-term-34kDa salivary peptide in blood (salivary biomarkers of Aedes exposure), measured using ELISA
3. Pupae per person (number of pupae found per 100 households examined) to evaluate the mosquitoes density/presence, measured by visual inspection
Secondary outcome measures
Measured every 6 months over a 3-year period:
1. Anti-dengue IgG antibodies waning rates (from positive at baseline to negative at follow-up), measured using ELISA
2. Additional entomological indexes, based upon visual inspection
3. Self-reported health status and previous fever events, measured using a standardized questionnaire
4. Knowledge, attitudes and practices (KAP) changes, measured from focus groups and in-depth interviews
5. Household social capital, measured from focus groups and in-depth interviews
6. Social acceptability of activities, measured from focus groups and in-depth interviews
7. Implementation and adaptability processes, measured from focus groups and in-depth interviews
8. Potential for sustainability (intervention), measured from focus groups, in-depth interviews, and document analysis
9. Empowerment of individual and communities, measured from focus groups and in-depth interviews
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
Eligibility will be evaluated on three levels: clusters, households, and individual. The inclusion criteria is:
1. Any of the 3,020 census tracts from the 2010 Census
2. Households permanently inhabited
3. Children aged 3 to 9 years
Target number of participants
There will be 34 clusters in each arm of 80 children aged between 3 to 9 years old for a total of 5,440 children enrolled in the study.
Participant exclusion criteria
1. Census tracts where interventions outside of vector control standard practices occurred within the last 5 years
2. Census tracts deemed to insecure for study personnel (determined based upon the opinion of the research team and stakeholders)
3. Clusters with less than 120 households
4. Abandoned or non-permanent households or households with the intention to move outside of the household during the study period
6. Children with chronic disease or other health condition that preclude participation in the study
7. Parents or guardians who are unable to give informed consent
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Universidade Estadual do Ceara
Av. Dr. Silas Munguba, 1700 Campus do Itaperi
Public Health Research Institute, University of Montreal
Institut de recherche en santé publique de l'Université de Montréal
7101 avenue du Parc
Universidade Estadual do Ceara
Av. Dr. Silas Munguba
Institut de recherche pour le développement (IRD)
bd de Dunkerque
Secretaria Municipal de Saúde de Fortaleza
Rua Sāo José
01 - Centro
Canadian Institutes of Health Research
Instituts de Recherche en Santé du Canada, CIHR
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
The trialists intend to publish the study protocol and will make this available on the study website (which will be developed shortly).
The Knowledge Transfer (KT) process is integrated into their approach. They will share study results with the participants, including after the baseline assessment, through community meetings and the study website. Parents or guardians of children participants will be informed of the status of their child’s test results via a call from a study nurse. Wide dissemination of findings will occur with the Fortaleza Health Department and the Brazilian National Institute of Health through deliberative workshops and policy briefings. The trialists will also disseminate their results to other endemic countries through policy briefs as well as through international and regional Aedes and arboviruses networks, notably AEDES Network, DENTARGET, WHO/TDR, and PAHO. They will disseminate to the broader scientific community through open access publications and presentations at national and international conferences. They will also make aggregate data of the study’s findings publicly available, after publication, through the study website.
IPD sharing statement
The trialists' intention is to have participant level data stored in a repository although the details of this have not yet been confirmed.
Intention to publish date
Participant level data
Stored in repository
Basic results (scientific)