Abstract
Problem: On 26 September 2025, a fire at the National Information Resources Service Data Centre disabled the Infectious Disease Information System and halted automated surveillance in the Republic of Korea.
Context: The information system is the backbone of the country’s infectious disease surveillance network, integrating clinical, laboratory and epidemiological data via an automated electronic notification interface. Diseases are categorized into Classes 1–4, based on their potential impact and level of urgency. This supports decision-making on outbreak preparedness and response.
Action: The Korea Disease Control and Prevention Agency immediately designated its 1339 call centre as the reporting channel for urgent Class 1 infectious diseases. Within 24 hours, it had developed temporary cloud-based reporting tools enabling local health centres to report Class 2 and 3 diseases. Using Naver Forms, health centres reported only essential infectious disease variables based on notifications received from medical institutions via fax or phone. Sentinel surveillance data for Class 4 diseases were collected using standardized Excel templates via Google Forms. Interagency meetings were routinely held to ensure transparent coordination.
Outcome: Class 1 notifications continued through the 1339 hotline during the outage, which lasted until 28 October 2025. Following system restoration, disease-specific totals from the temporary cloud-based reporting tools and the restored datasets showed high overall consistency (Pearson correlation coefficient = 0.99, P < 0.001).
Discussion: Essential surveillance functions can be maintained during a nationwide IT outage through adaptive reporting mechanisms and strong institutional coordination. Infrastructure redundancy, disaster recovery capacity and regular simulation exercises are also critical for maintaining surveillance continuity.