[Analysis of the Pertussis Status in Jeju Special Self-Governing Province in 2024]

Pertussis is a sporadic infectious disease, and no large-scale outbreaks have previously occurred in Jeju However, an unprecedented outbreak was anticipated by 2024. This study aimed to analyze the pertussis cases reported in Jeju in 2024 and share the findings.

We analyzed pertussis cases reported to the Korea Disease Control and Prevention Agency Integrated Disease Management System between January 1 and December 31, 2024. Epidemiological investigation reports were used to assess cases' scale, location, demographics, and clinical characteristics. Cross-validation was performed using infectious disease reports, laboratory test results, and cluster outbreak reports to determine outbreak size, location, and transmission patterns.

Most cases were reported in Nohyeong-dong, Jeju City (218 cases), and Daecheon-dong, Seogwipo City (13 cases). The number of cases increased in June and peaked in July. Among the 960 reported cases, 832 were students, and males (606 cases) were nearly twice as affected as females (354 cases). The main clinical symptom was coughing, including mild cough (99.6%), whooping cough (17.2%), and paroxysmal cough (29.3%). Although 844 cases (87.9%) had received at least one vaccine dose, only 641 cases (66.8%) had completed the full vaccination series. There were 45 cluster outbreaks in schools, accounting for 678 cases (70.6%).

Cases were concentrated in densely populated areas, predominantly affecting males and school-aged children rather than infants. Cases mainly occurred during the summer, and the sixth-dose vaccination rate was lower than the fifth-dose rate. This study provides a comprehensive analysis of the pertussis outbreak in Jeju and highlights the need for revised response measures to improve pertussis prevention and management.