Public health surveillance systems in Senegal are crucial for monitoring diseases and managing healthcare resources effectively. A mixed-methods approach including quantitative data analysis and qualitative interviews was employed to assess system performance. Participants were randomly assigned to either an intervention group or control group within the surveillance framework. The proportion of timely diagnoses increased by 15% in the intervention group compared to the control, indicating improved clinical outcomes due to enhanced surveillance practices. This study underscores the importance of rigorous methodological evaluation for public health surveillance systems and highlights the potential benefits of targeted interventions. Public health authorities should prioritise continuous system improvement based on feedback from this trial and future evaluations. public health, surveillance systems, clinical outcomes, randomized field trial Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.