The Infodengue–Mosqlimate Dengue Challenge (IMDC) is an international scientific initiative designed to improve dengue outbreak forecasting in Brazil using computational models and integrated datasets. IMDC is a collaborative data science experiment applied to public health, bringing together epidemiological, environmental, demographic, and climate data to develop predictive models based on different methodological approaches. These models aim to support decision-making and strengthen dengue surveillance and control strategies. The challenge operates as a modeling sprint, in which teams of researchers develop models to estimate the expected number of dengue cases for the upcoming season in selected cities and states across Brazil. The main objectives of IMDC are:
- To build an international community of dengue modelers
- To develop and compare different predictive modeling approaches
- To create ensemble models that combine forecasts from multiple teams
- To continuously evaluate and improve model performance
History
The first edition of the Infodengue–Mosqlimate Dengue Challenge (IMDC) was organized by the InfoDengue and Mosqlimate projects in 2024 and introduced the Dengue Forecast Sprint format. This inaugural edition brought together research teams to develop dengue forecasting models for Brazil. A total of six teams participated, contributing eight predictive models. During this edition, a framework was established for the standardized submission of forecasts via GitHub, as well as a methodology for building ensemble models that combine forecasts from multiple teams. The second edition of the IMDC, held in 2025, significantly expanded the scale of the challenge and strengthened international collaboration. This edition involved 15 research teams, contributing 19 different predictive models and bringing together a total of 52 researchers. In both challenges, the main outcome was the prediction of the weekly number of dengue cases by Brazilian state. To evaluate model performance, three retrospective validation tests were defined using historical data from 2010 to 2025, followed by a final real-time forecasting target. The Mosqlimate team also developed a collective ensemble model, combining forecasts from multiple teams to improve the accuracy and robustness of dengue predictions in Brazil. Among the main achievements of the 2024 and 2025 IMDC editions are:
- Establishment of a collaborative framework for multi-team forecasting
- Development and improvement of a data infrastructure and standardized model submission system
- Development and evaluation of dengue forecasting methodologies
- Creation of evaluation methods and metrics to assess predictive model performance
- Development and refinement of ensemble models that combine forecasts from multiple teams
Dissemination
The two challenges brought together institutions from several countries, including Brazil, the United States, the United Kingdom, Germany, Italy, Spain, Saudi Arabia, and South Africa. Results were disseminated through several events and publications:
- Validation results webinar
- International webinar (2025)
- Technical reports (in Portuguese) published in 2024 and 2025
- Scientific article describing the methodology and results
Impact
The IMDC has contributed to:
- The development of more robust epidemiological forecasting tools
- Improved support for public health decision-making
- Strengthening international collaboration in infectious disease modeling
3rd IMDC edition
Registration for this year’s edition opens on April 1, 2026. To participate, visit the Registration page. Detailed information about the challenge can be found on the Instructions page. The full schedule of dates for this edition is provided below.
Important dates:
- April 1, 2026 – Challenge launch and opening of team registrations.
- May 15, 2026 – Deadline for team registration.
- July 1, 2026 – Submission deadline for validation round results.
- July 31, 2026 – Webinar: Presentation of validation round results.
- September 10, 2026 – Submission deadline for 2026–2027 forecasts.
- September 22, 2026 – Internal webinar for teams to present model methodologies.
- October 15, 2026 – International webinar: Technical results of IMDC 2026.
- October 30, 2026 – International webinar: IMDC 2026 results for the general audience.
Blogs
2nd InfoDengue–Mosqlimate Dengue Challenge (IMDC): Results of the Dengue Forecast Challenge in Brazil
The second InfoDengue–Mosqlimate Dengue Challenge (IMDC) brought together researchers and modeling teams from around the world with an ambitious goal: to improve dengue outbreak forecasts in Brazil using climatic and epidemiological data.
The IMDC results presentation event highlighted major technical advances and international collaboration in tackling mosquito-borne diseases. In the first part, the presenters shared the ensemble model results, which combine forecasts from multiple approaches to generate more robust estimates of dengue cases. The discussion covered performance comparisons, uncertainty analysis, and next steps to enhance the integration of climate and epidemiological data in forecasting models.