Development of a Training Program for Epidemiological Investigation of Outbreaks of Unknown Cause

Clusters of unexplained illness occurrence can span multiple administrative domains, delaying initial response and role coordination. Non-infectious clusters with unclear exposures, long latency periods, or low disease specificity are particularly difficult to investigate and manage. This study describes the development and pilot implementation of a training program for epidemiological investigation for such clusters.

We synthesized materials from a 3-year project conducted during 2024-2026, including the initial proposal, expert reviews, presentation materials, reports, educational textbooks, pilot training records, and satisfaction survey results. The program was refined through research meetings, expert discussions, workshops, demonstrations, and the production of textbooks and video materials. Delivery of these materials was done in the form of online didactic sessions and scenario-based practical training that was conducted online and in person.

The program covered the concept and policy relevance of unexplained clusters, relevant investigation procedures, the generation of hypotheses, methods of data collection, risk communication strategies, techniques of interagency coordination, and case-based approaches to decision-making. Scenario exercises were designed to help trainees work through problem definition, exposure assessment, stakeholder coordination, interpretation of uncertain evidence, and communication of interim findings. The program also emphasized the policy blind spots that were created by unclarity of jurisdiction and the need to coordinate public health responses with environmental health functions.

Training for non-infectious clusters of unexplained illness should go beyond lecture-based knowledge transfer and include problem-based learning, scenario discussions, and practical coordination exercises. Continuous revision based on field cases and formal evaluation of educational effects are needed for sustainable implementation.