Public health surveillance systems in Senegal are crucial for monitoring infectious diseases such as malaria and tuberculosis. However, their reliability under varying conditions is poorly understood. A quasi-experimental study was conducted to assess the reliability of public health surveillance systems in Senegal. Data were collected from multiple healthcare facilities representing various geographical regions and operational contexts. The analysis revealed a significant variability in system performance, with an average error rate of 15% across different settings, indicating room for improvement in system accuracy and consistency. The quasi-experimental design successfully highlighted the need for system upgrades to enhance reliability, particularly in resource-limited settings such as rural areas. Public health authorities are advised to prioritise upgrading surveillance systems with robust algorithms and regular maintenance protocols to ensure consistent performance across all operational environments. Treatment effect was estimated with $\text{logit}(p_i)=\beta_0+\beta^\top X_i$, and uncertainty reported using confidence-interval based inference.