Zika, Dengue and Chikungunya: Multisectoral approaches for developing solutions applicable to public health for very poor people living in and around the biggest open dump in Latin America in Brasilia, Brazil
Overview
Why this project?
Aedes aegypti is a mosquito species responsible for transmitting several arboviral diseases. In 2024, more than 3 million dengue cases were reported. Most of these were in Brazil.
Arboviruses are greatly affecting Brazil's population. Up to April 2024, Brazil recorded:
Multisectoral approach
The emergence of arboviruses in Brazil has been affected by:
Lack of selective garbage collection
Inadequate water storage
People living in open dump sites
To improve the prevention and control of dengue, zika and chikungunya, it was necessary to investigate the environmental risk factors associated with the transmission of arboviruses. Mosquitoes breed in inadequately stored water and in pools of water that collects in waste. It was therefore important to assess the impact of waste disposal in high transmission areas and to monitor the quality of potable water.
To best inform control actions, the correct identification of mosquito species is essential to collect and analyze entomological data related to the mosquito species responsible for arbovirus transmission. A mobile app was developed and validated to assist with rapid species identification.
There is a need to develop new identification strategies that are:
- easier to use,
- more illustrated and self-explanatory,
- designed to reach a wider audience,
- appropriate for rapid identification.
The aim
The overall aim of this work is to develop public health-applicable solutions to reduce the burden of arboviruses among vulnerable populations in Brasília, Brazil.
Objectives
Specific objectives include the following:
Assessing sanitation conditions in two different areas of Estrutural City and correlating these with cases of arboviral disease. Assessments included selective waste collection and quality of water for human consumption.
Improving entomological surveillance of urban mosquitoes by analyzing the population density of Ae. aegypti, and developing, improving and validating the CULICIDEX app for the identification of mosquito species of interest in public health.
Conducting qualitative research and health education in Estrutural City to better understand the population’s needs and awareness of sanitation. This included a focus on why and how water is stored in homes, as well as an analysis of the discomfort caused by mosquitoes in the study areas.
Research sites
The multidisciplinary project compared two areas (with and without sanitation) within Estrutural City, the poorest city in Brasília, which hosts the largest open dump in America Latina and second largest in the world.
Key findings
Assessing sanitation conditions
The study highlighted significant differences in sanitation between two areas of Estrutural City: one with and one without sanitation facilities. Water quality analysis in areas without sanitation found dangerous levels of contamination, including total coliforms and Escherichia coli, beyond safe limits. Dengue incidence was also higher in these areas, emphasizing the urgent need for interventions to improve sanitation and mitigate health risks in vulnerable communities.
Improving entomological surveillance
- Research evidence on Ae. aegypti frequency and density in a low-income area in Brasilia
An 11-month entomological survey in 60 houses in Estrutural revealed a high density of Ae. aegyptimosquitoes, underscoring the impact of poor sanitation and water quality on mosquito prevalence in the area.
- New strategic approach to identifying mosquitoes of interest
A new app was developed to identify Culicidae in 26 mosquito species across 11 genera. The app was available from app stores until October 2023; training was provided for scientists and professionals on how to use the tool effectively.
Conducting qualitative research and health education
- Health education activities for water storage, garbage disposal and installation of a voluntary waste delivery station
Despite delays in building a solid waste facility due to elections, the Urban Cleaning Service installed garbage disposals at key locations in unserviced areas. Engagements with residents highlighted the need for trash cans and bags for effective waste management, leading to awareness campaigns on proper garbage disposal practices.
- Understanding population experiences regarding water, vectors and the intersection of the two
The research uncovered valuable knowledge within the community on dengue vectors, detailing factors contributing to mosquito identification, as well as dengue prevalence, and existing prevention efforts. These insights pave the way for effective arbovirus control strategies in high-risk areas, reinforcing public health policies and essential services for at-risk communities.
Research Components
Overview
This project utilized diverse methodological approaches across three objectives.
Assessing sanitation conditions
- Analysis of the sanitation conditions conducted in the two identified areas of Estrutural City included selective waste collection and the quality of drinking water, which was correlated with cases of arboviral diseases.
- The team visited 30 houses in each area, assessing the presence of debris, open sewage disposal, wooden structures, and ground water reservoirs. Additionally, water samples were collected for analysis, which focused on microbiological, physical, and chemical parameters.
- A multiparameter probe and a liquid chromatography analysis were used.
Improving entomological surveillance
All participants were trained at the Laboratory of Medical Parasitology and Vector Biology to collect mosquitoes, identify and process entomological samples.
In each area, 30 dwellings were selected for adult mosquito capture using light-weight mosquito aspirators. Mosquitoes were dislodged from typical resting surfaces and captured by a trained collector.
Houses were sampled two to three times per month.
Conducting qualitative research and health education
- In collaboration with the Basic Health Unit, 91 members of the community were surveyed on vaccination schedules.
- An autoethnography on waste picking was published in Global Health Research and a manuscript was submitted to the Waste Management and Human Health.
Sampling
Sampling efforts combined both qualitative and quantitative approaches, such as semi-structured interviews and active trapping. Sixty houses were selected from two areas for direct observation and mosquito collection, and interviews were conducted with 110 inhabitants for qualitative research.
Collection of data
Data collection included environmental observations, water quality testing, mosquito capture and identification, and community interviews. This encompassed physical, chemical, and biological analysis of water, along with the development and use of the CULICIDEX app for mosquito identification.
Quality assurance
Community health agents carried out disease prevention and health promotion activities, based on Popular Health Education references and the guidelines of the Unified Health System (SUS).
Quality assurance measures included rigorous sampling methodologies, adherence to health standards for water quality, and validation of the CULICIDEX app for accurate mosquito identification.
Ethical consideration
The project's ethical procedures included obtaining informed consent for interviews and ensuring participant anonymity. Interventions, such as water tank and waste bag distribution, were also implemented to improve living conditions without exacerbating existing vulnerabilities.
Research uptake
Objectives
Results from this research will be used to:
- achieve a better understanding of the occurrence and transmission of diseases related to Ae. aegypti,
- improve surveillance and control of arboviruses through the implementation of regular basicsanitation actions,
- ensure consistent uptake of actions through joint participation of the relevant institutions, and
- encourage community engagement through workshops and meetings held periodically in the areas of study.
Uptake activities
The results will be widely disseminated in congresses, meetings and symposia using printed and digital scientific articles. Teaching materials will also be produced for schools, vector control institutions and medical entomology laboratories.
The preliminary data demonstrate a significantly higher mosquito population in regions lacking fundamental sanitation facilities, with approximately seven times more mosquitoes observed compared to areas with adequate sanitation. Seasonal variations were also evident, with an increase in mosquito numbers during the wetter months aligning with expectations. Moving forward, our research will employ modeling analyses to investigate the question: Which variable (or combination of variables) best explains the variation in mosquito density in the area?
Products related to the project
Abstracts published in conferences:
OBARA, M.T.; LEAL, J.F.C.; LIMA, M.S.F.; SOARES, P A.S.; MACEDO, GLAUCO O.; CARVALHO, B. L.; SOUZA, P.F.; GOMES, D.F.; SANTOS, T.S.S.N.; GURGEL-GONÇALVES, R. Control of Aedes aegypti in a socioeconomically vulnerable area in Brasília using pyriproxyfen dissemination by mosquitoes: an exploratory analysis. In: 58th Congress of the Brazilian Society of Tropical Medicine, 2023, Salvador.
ARAÚJO, T.O.; GURGELGONÇALVES, R.; ROCHA, D.A.; ALMEIDA, M.R.; OBARA, M.T. CULICIDEX: Key to identification of urban and periurban mosquitoes in Brazil, 2023. (Congress, Paper Presentation). Additional references: Brazil/Portuguese. Dissemination means: Digital means; Location: Salvador; City: Salvador; Event: 58th Congress of the Brazilian Society of Tropical Medicine; Promoter/financier institution: SBMT
ARAÚJO, T.O.; GURGEL-GONÇALVES, R.; ROCHA, D.A.; ALMEIDA, M.R.; OBARA, M.T. Development of an application (CULICIDEX) for identification of mosquitoes of importance in public health, 2023. (Other, Work Presentation) Additional references: Brazil/Breton; Location: Mané Garrincha; City: Brasília; Event: IV International Meeting on Innovation in Health - IV INOVATEC; Promoter/financier institution: University of Brasília
OBARA, M.T.; LIMA, M.S.F.; SOARES, P.A.S.; MACEDO, GLAUCO O.; SILVA, B.M.; SOUSA, M.S.; SOUZA, PF; SANTOS, T.S.S.N.; GONÇALVES, N.M.; ASSIS, P.G.; TEIXEIRA, J.M.S.; MARTINS, A.C.S.; CRUVINEL, V.R.N.; GURGELGONÇALVES, R. Sanitary conditions and density of urban mosquitoes: a descriptive analysis in two poor neighborhoods in Brasília, Federal District, Brazil, 2023. (Conference, Paper Presentation). Additional information: Brazil/Portuguese; Location: Tiradentes University; City: Aracaju; Event: XXVIII Congress of the Brazilian Society of Parasitology; Promoter/financier institution: SBP
ZOLNIKOV, T.R., CLARK, T., FURIO, F., YASOBANT, S., MARTINS, A.C.S., CRUVINEL, V.R.N., OBARA, M. ENSURE Waste and Recycling. Apr 10-13. San Francisco, CA. “Look, it’s a dengue mosquito”: A qualitative study on open-air dumpsites and vectorborne diseases. [Podium and moderator].
MARTINS, A.C.S.; ANDRADE, F.R.D.; OBARA, M.T.; MUNIZ, D.H.F.; GONÇALVES, R.G.; CRUVINEL, V.R.N. Is water healthy? Evidence of an extremely vulnerable location in the Federal District. In: Annals of the Brazilian Interdisciplinary Conference in Science and Technology, 2023, Online. Proceedings of the Annals of the Brazilian Interdisciplinary Congress in Science and Technology. Recife: Even3, 2023. p. 1.
MARTINS, A.C.S.; SILVA, É.N.D.; ANDRADE, F.R.D.; CRUVINEL, V.R.N.; OBARA, M.T.; GONÇALVES, R.G. Actions to confight against arboviroses in an extremely vulnerable city in the Federal District. Vol. 2 No. Supl.3 (2022): Summaries of the III National Congress of Innovations in Health (CONAIS 22). Available at: https://bjcasereports.com.br/index.php/bjcr/article/view/conais22_28_33/conais22_28_33
New approach to identify mosquitoes - Apps
- https://apps.apple.com/br/app/vetordex/id1602553121
- https://play.google.com/store/apps/details?id=vetordex.com
Published Papers
ZOLNIKOV, T.R. (2023) Stop treating waste pickers like garbage: An autoethnography on informal waste picking in Brazil, Global Public Health, 18:1, 2201328, DOI:10.1080/17441692.2023.2201328
ZOLNIKOV, T.R.; CLARK, T.; FURIO, F.; YASOBANT, S.; MARTINS, A.C.S.; CRUVINEL, V.R.N.; OBARA, M.T. Look, It's a Dengue Mosquito: A Qualitative Study on Living Near Open-Air Dumpsites and Vector-Borne Diseases. Advances in Environmental and Engineering Research, v.04, p. 1-25, 2023.
Collaborating partners
The main executing institution is the University of Brasília, in partnership with three institutions based in the Federal District:
- Water, Energy and Sanitation Regulatory Agency (ADASA)
Environmental Health Surveillance Department (DIVAL)
Urban Cleaning Service (SLU)
Contact details