The Role of Event Intelligence in Public Health Emergencies: A Systematic Review of Detection, Verification, Risk Assessment and Response to Public Health Threats (Preprint)

<sec> <title>BACKGROUND</title> <p>Event intelligence has become an integral component of modern public health surveillance by supporting the early detection, verification, risk assessment, and management of public health threats through the integration of multisource information. Although event intelligence has expanded rapidly in response to emerging infectious diseases and other public health emergencies, the evidence remains fragmented across surveillance systems, analytical approaches, implementation settings, and operational contexts.</p> </sec> <sec> <title>OBJECTIVE</title> <p>This systematic review aimed to synthesize the contemporary evidence on event intelligence for public health emergency preparedness and response, with particular emphasis on its conceptualization, surveillance architectures, information sources, analytical approaches, operational functions, implementation characteristics, governance, outcomes, barriers, and enabling factors.</p> </sec> <sec> <title>METHODS</title> <p>A systematic review was conducted in accordance with the PRISMA 2020 statement. Literature searches were performed in PubMed/MEDLINE, Scopus, Web of Science, Embase, Global Health, Google Scholar, eligible institutional sources, and supplementary citation searches. Studies addressing event intelligence, epidemic intelligence, event-based surveillance, and related surveillance approaches in public health emergency settings were screened against predefined eligibility criteria. Data were extracted on surveillance architectures, data sources, analytical approaches, implementation characteristics, governance, operational functions, outcomes, barriers, and enabling factors. Owing to methodological heterogeneity, findings were synthesized narratively.</p> </sec> <sec> <title>RESULTS</title> <p>The search identified 6784 records, of which 74 studies met the inclusion criteria. The evidence demonstrated that contemporary event intelligence integrates indicator-based and event-based surveillance, drawing on multisource information from official surveillance systems, laboratories, community networks, media monitoring, digital platforms, and open-source intelligence. Event intelligence consistently supported six interconnected functions: detection, verification, risk assessment, situational awareness, preparedness, and response. Advances in digital surveillance, artificial intelligence, natural language processing, and machine learning improved information processing, signal prioritization, and operational efficiency. However, expert epidemiological judgment remained essential for verification, contextual interpretation, and decision-making. Successful implementation depended on effective governance, interoperability, multisectoral collaboration, workforce capacity, standardized operating procedures, and sustainable institutional investment.</p> </sec> <sec> <title>CONCLUSIONS</title> <p>Event intelligence has evolved into an integrated public health intelligence capability that strengthens preparedness, situational awareness, and emergency response by transforming multisource surveillance information into actionable intelligence. Future efforts should prioritize interoperable surveillance systems, standardized evaluation frameworks, sustainable workforce development, and coordinated governance while ensuring that advances in artificial intelligence and digital surveillance complement expert public health decision-making.</p> </sec>