ABSTRACT:
The Dengue Observatory, grounded in action research, is a community-based health surveillance initiative that integrates science and social participation to address the challenges posed by the proliferation of Aedes aegypti in Rio de Janeiro. In the context of a sharp increase in dengue cases in early 2025, the project is based on the recognition that mosquito dynamics are strongly conditioned by climatic variables, urban morphology, and socio-spatial inequalities that structure situations of climate and health injustice. The research is conducted in the city’s Health Programmatic Area 2.2 and combines the mapping of Local Climate Zones (LCZ), meteorological monitoring, and entomological surveillance through ovitraps. LCZ were delineated based on land use and land cover characteristics, urban form, and surface properties. Meteorological stations were installed to provide continuous records of atmospheric conditions, and 32 ovitraps were distributed across public schools, residences, and community spaces, covering six LCZ classes, with weekly collections. The analyses integrated descriptive statistics, Spearman correlation, and machine learning models (Random Forest) to assess the relationships between climate, vector infestation, urban typologies, and reported dengue cases. The results indicate high egg hatching rates and a positive and statistically significant association between air temperature, particularly minimum temperatures, and infestation indices. The highest egg densities were concentrated in compact LCZ of medium- and high-rise development, highlighting greater population exposure in densely built areas characterized by reduced ventilation, increased heat retention, and precarious urban infrastructure. Beyond the analytical results, the project maintains an open-access digital platform and implements educational actions, transforming schools into community-based entomological laboratories to strengthen local surveillance networks.