Introduction: The city of Santa Fe (Argentina) is highly exposed to environmental conditions that favor outbreaks of dengue and leptospirosis. Official public health campaigns often rely on top-down compliance-based approaches, underestimating the potential of community participation. This study aimed to quantify the effectiveness of participatory strategies compared to conventional methods through controlled community trials in four riverside neighborhoods with similar socio-environmental conditions.

Methodology: In 2024/2025, two intervention sectors (Vuelta del Paraguayo / Manzana 2) and two control sectors (Colastiné / Boca) were established (n=80 households per site). The intervention involved training cycles for health promoters based on popular education and participatory action research (PAR), promoting community dialogue and territorial planning. Control areas received traditional, non-participatory campaigns. A longitudinal pre-post design was used. Indicators included: knowledge, attitudes, practices, and perceptions (KAPP); abundance of Aedes aegypti adults, larvae, and breeding sites; and rodent activity monitored through hair traps. Data were analyzed using generalized linear mixed models (GLMM) and logistic regressions to assess the interaction effect between treatment condition (participatory vs. control) and time in both trials.

Results: Significant interaction effects were found (p < 0.05). The probability of finding potential larval breeding sites was reduced by 39% (OR: 0.61), larval breeding sites by 41% (OR: 0.59), and Ae. aegypti adults by 31% (OR: 0.69) compared to control groups (p < 0.05). Additionally, rodent activity was reduced by 44% (OR: 0.56). Furthermore, a significant increase in risk knowledge and perception was observed.

Conclusion: Participatory methods demonstrate greater efficacy than traditional approaches in reducing biological risk indicators. Community empowerment acts as a cost-effective strategy by fostering social sustainability, reducing dependence on recurring chemical interventions, and mitigating the risk of zoonotic disease transmission in vulnerable settings