The first confirmed community transmission of coronavirus disease 2019 in Daegu Metropolitan City, South Korea, occurred on February 18, 2020. In the following 70-day period, approximately 6000 new cases occurred, severely impacting the medical service system. This study investigated the crisis-impact on the local emergency transport system.Emergency medical service activity reports were retrospectively reviewed to determine patient demographics and initial vital signs. Delay in reaching the patient, transporting the patient to the hospital, and returning to the fire station were assessed and categorized based on patients' initial vital signs. The study period was divided into 4 groups (1/1-2/18, 2/19-3/3, 3/4-3/31, and 4/1-04/30) and intergroup differences were analyzed.When compared to Period 1, the time-difference between the request to attend a scene and arrival at the scene was delayed in Periods 2, 3, and 4 by 4 minute 58 s, 3 minute 24 seconds, and 2 minute 20 seconds, respectively; that between arriving at the scene and at the hospital was delayed by 7 minute 43 seconds, 6 minutes 59 seconds, and 4 minutes 30 seconds, respectively; and that between arriving at the hospital and returning to the fire station was delayed by 29 minute 3 second, 25 minute 55 second, and 18 minute 44 second, respectively. In Period 2, for patients with symptoms of severe illness when compared to patients lacking such symptoms, the time-difference between the request to attend the scene and arrival at a hospital and between arrival at the hospital and returning to the fire station were 6 to 23 minute and 12 to 48 minute longer, respectively. Most of the delays impacted patients with a fever. In terms of condition, the statistical effect size for delay in transport time was from large to small: fever, hypoxia, abnormal respiratory rate, respiratory symptom, and hypotension.Outbreaks of infectious disease cause a paradoxical state in emergency medical transport systems, inducing delays in the transport of severely ill patients. Therefore, maintenance and improvement of the medical service system for both patients with infectious disease and those with other severe illnesses is required.