EcoHealth approach for dengue control
| ISRCTN | ISRCTN66131315 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN66131315 |
| Secondary identifying numbers | 201803PJT-400444-RC2-CFCA-120159 |
- Submission date
- 25/09/2018
- Registration date
- 01/10/2018
- Last edited
- 07/02/2025
- Recruitment status
- No longer recruiting
- Overall study status
- Ongoing
- Condition category
- Infections and Infestations
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. In 2025, the study location was updated to Dhaka, Bangladesh, where children 2 to 12 years old will be recruited.
Who can participate?
Households with children aged 2 to 12 years
What does the study involve?
Participating areas are randomly allocated to one of two groups. Household visits occur at baseline and after 2 years of follow-up to administer questionnaires and collect dried blood spot (DBS) samples. Clusters will be allocated to intervention or control immediately after the baseline collection. In the intervention clusters, 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, according to the study site. Rates of dengue infection and the number of adult Aedes mosquitos are measured at baseline and endline over a 2-year period.
What are the possible benefits and risks of participating?
The results will help develop evidence-based mosquito control programs in 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/Bangladesh 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 on 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 (Site 1: Fortaleza, Brazil)
BRAC University (Site 2: Dhaka, Bangladesh)
When is the study starting and how long is it expected to run for?
October 2018 to March 2027
Who is funding the study?
Canadian Institutes of Health Research (Canada)
Who is the main contact?
Dr Kate Zinszer
Contact information
Scientific
School of Public Health
University of Montreal
7101 Park Ave
Montreal
H3N 1X9
Canada
 ORCID ID |
0000-0003-1388-1145 |
|---|
Study information
| Study design | Two-arm cluster randomized controlled trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Cluster randomised trial |
| Study setting(s) | Community |
| Study type | Prevention |
| Participant information sheet | Not available in web format, please use contact details to request a participant information sheet. |
| Scientific title | Improving Aedes control through community mobilization to reduce dengue incidence in Brazil: a cluster randomized controlled trial |
| Study hypothesis | The principal research question is: does community mobilization reduce the risk of dengue virus infection compared to usual dengue control practice in Fortaleza, Brazil. Added 07/02/2025: Note that the study site has been modified to Dhaka, Bangladesh. |
| Ethics approval(s) | 1. Approved 17/12/2024, Health Research Ethics Committee at the University of Montreal (CERSES, Bureau de la conduite responsable en recherche, Université de Montréal) (Université de Montréal 3333, chemin Queen-Mary, Montréal , H3V 1A2, Canada; +1 (0)514 343-6111 #2604; cerses@umontreal.ca), ref: # 2024-6439 2. Approved 16/11/2024, Research Review Committee (RRC), International Centre for Diarrhoeal Disease Research, Bangladesh (68, Shaheed Tajuddin Ahmed Sarani, Mohakhali, Dhaka, 1212, Bangladesh; +880 (0)1713039813; sasarker@icddrb.org), ref: PR-24128 3. Approved 10/10/2024, Institutional Review Board of the BRAC James P Grant School of Public Health, BRAC University (6th Floor, Medona Tower, 28 Mohakhali Commercial Area, Bir Uttom A K Khandakar Road, Dhaka, 1213, Bangladesh; +880 (0)2-48812213-18; irb-jpgsph@bracu.ac.bd), ref: IRB-2024-IS-25 Site 1: 1. Approved 30/01/2019, Health Research Ethics Committee at the University of Montreal (Bureau de la conduite responsable en recherche, Université de Montréal, C.P. 6128, succursale Centre-ville, Montréal, Québec, Canada H3C 3J7; Tel: +1 (0)514 343 6111 x27395; Email: camille.assemat@umontreal.ca), ref: 18-141 2. Approved 14/12/2018, Comité de Ética em Pesquisa da Universidade Estadual do Ceará (State University of Ceará, Av. Silas Munguba 1700, Itaperia, 60.714-903, Fortaleza – CE, Brazil; Tel: +55(0)85 3101 9890; Email: cep@uece.br), ref: 3.083.892 Site 2: Approved by the committees listed above |
| Condition | Dengue infection |
| Intervention | 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 86 children aged between 2 to 12 years old for a total of 5,848 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. |
| Intervention type | Behavioural |
| Primary outcome measure | Current primary outcome measures as of 07/02/2025: Measured twice over a 2-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. Adult female mosquitoes per person (number found per 100 households examined) to evaluate the mosquitoes' density/presence, measured by visual inspection Previous primary outcome measures: 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 | Current secondary outcome measures as of 07/02/2025: Measured twice over a 2-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 questionnaires 5. Household social capital, measured from questionnaires 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 Previous 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 study start date | 01/10/2018 |
| Overall study end date | 31/03/2027 |
Eligibility
| Participant type(s) | All |
|---|---|
| Age group | Child |
| Lower age limit | 2 Years |
| Upper age limit | 12 Years |
| Sex | Both |
| Target number of participants | There will be 34 clusters in each arm of 86 children aged between 2 to 12 years old for a total of 5,848 children enrolled in the study. |
| Participant inclusion criteria | Site 1 (Fortaleza, Brazil): Eligibility will be evaluated on three levels: clusters, households, and individual. The inclusion criteria are: 1. Any of the 3,020 census tracts from the 2010 Census 2. Households permanently inhabited 3. Children aged 3 to 9 years Added 07/02/2025: Site 2 (Dhaka, Bangladesh): Eligibility will be evaluated on three levels: clusters, households, and individual. The cluster inclusion criteria are: for areas of Dhaka city will be selected for inclusion in the study based on recent data on dengue prevalence. Any households within the selected clusters will be eligible to participate in the study if they 1. Have at least one child between the ages of 2 and 12 years old, who has lived in the household for at least 6 months, and 2. There is a parent/guardian or other adult caregiver that can provide informed consent. |
| Participant exclusion criteria | Site 1 (Fortaleza, Brazil): 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 Added 07/02/2025: Site 2 (Dhaka, Bangladesh): Clusters will be excluded from the study if: 1. They experienced interventions outside of standard vector control practices within the last two years 2. They contain less than 62 households as our formative study suggested that 62-70 households are required to obtain the needed sample size. Households will be excluded from participating in the study if: 1. They intend to move outside of the cluster during the period of the study (2024-2027) 2. They do not have any children between the ages of 2 and 12 years old 3. The child has a chronic disease or other health condition that precludes participation in the study 4. There is not a parent/guardian or other adult caregiver that can provide informed consent. Additionally, households will be excluded from participating in the entomology assessment if there is no electricity in their home (electricity is required for the mosquito traps). There are no exclusion criteria for the qualitative components of the study. |
| Recruitment start date | 15/10/2019 |
| Recruitment end date | 31/03/2025 |
Locations
Countries of recruitment
- Bangladesh
- Brazil
Study participating centres
Fortaleza
60.714.903
Brazil
Dhaka
1213
Bangladesh
Dhaka
1212
Bangladesh
Sponsor information
University/education
Institut de recherche en santé publique de l'Université de Montréal
7101 avenue du Parc, bureau 3187-03
Montreal
H3N 1X9
Canada
| Website | http://www.irspum.umontreal.ca/fr-ca/accueil.aspx |
|---|---|
"ROR" |
https://ror.org/0161xgx34 |
University/education
Av. Dr. Silas Munguba, 1700
Fortaleza
60741-000
Brazil
| Website | http://www.uece.br/uece/ |
|---|
Government
Le Sextant
44, bd de Dunkerque
Marseille
90009
France
| Website | https://en.ird.fr/ |
|---|---|
|
"ROR" |
https://ror.org/00bnthp71 |
Government
Rua Sāo José, 01 - Centro
Fortaleza
60.060-170
Brazil
| Website | https://www.fortaleza.ce.gov.br/noticias/categoria/saude |
|---|
Funders
Funder type
Government
Government organisation / National government
- Alternative name(s)
- Instituts de Recherche en Santé du Canada, Canadian Institutes of Health Research (CIHR), CIHR_IRSC, Canadian Institutes of Health Research | Ottawa ON, CIHR, IRSC
- Location
- Canada
Results and Publications
| Intention to publish date | 01/03/2023 |
|---|---|
| Individual participant data (IPD) Intention to share | No |
| IPD sharing plan summary | Stored in repository |
| 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 plan | The trialists' intention is to have participant level data stored in a repository although the details of this have not yet been confirmed. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Protocol article | protocol | 14/02/2020 | 17/02/2020 | Yes | No |
| Results article | 25/09/2023 | 09/04/2024 | Yes | No |
Editorial Notes
07/02/2025: The following changes were made to the study record:
1. The study hypothesis, ethics approval, primary and secondary outcome measures, inclusion and exclusion criteria were updated.
2. The recruitment end date was changed from 01/07/2021 to 31/03/2025.
3. The overall study end date was changed from 31/03/2022 to 31/03/2027.
4. Bangladesh was added to the countries of recruitment.
5. BRAC James P Grant School of Public Health, BRAC University and International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B) were added to the study participating centres.
6. The target number of participants was changed from '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' to 'There will be 34 clusters in each arm of 86 children aged between 2 to 12 years old for a total of 5,848 children enrolled in the study'.
09/04/2024: Publication reference added.
17/02/2020: Publication reference added.
21/08/2019: Ethics approval details added, recruitment start date changed from 01/04/2019 to 15/10/2019.
