National Guidelines for Public Health Emergency Surveillance within the Brazilian Unified Health System

Abstract Objective: To describe the national guidelines for public health emergency surveillance within the Brazilian Unified Health System (Sistema Único de Saúde, SUS). Guidelines: The increasing frequency of health, environmental, and technological events has led to more public health emergencies, requiring systems capable of early threat detection, risk assessment, and timely response. Public health emergency surveillance is an integral component of health surveillance and encompasses strategies such as indicator-based, event-based, hospital-based epidemiological, mass gathering, wastewater, community-based, and participatory surveillance. These strategies are complementary and should be supported by continuous monitoring and systematic risk assessment, while incorporating multisectoral approaches, risk communication, and One Health. Strengthening public health emergency surveillance involves integrating information systems, building workforce capacity, institutionalizing contingency plans and standard operating procedures, activating situation rooms and emergency operations centers, conducting timely outbreak investigations, communicating risks, and conducting intra-action and after-action reviews. Factors such as territorial inequalities, social vulnerabilities, and population-specific characteristics influence risk exposure, detection capacity, and the impacts of emergencies, underscoring the need to incorporate equity into surveillance explicitly. Conclusion: The guidelines help consolidate public health emergency surveillance as a core component of preparedness and response within the Unified Health System, reinforcing participatory, integrated, and equity-oriented approaches to protect health and reduce harm.