Public health weekly report
Epidemiological Characteristics of Varicella Outbreaks in Daegu and Gyeongsangbuk-do, the Republic of Korea, 2022-2025
By Oh SH, Lee M, Kim S and 2 others.
Abstract
Objectives
This study aimed to characterize the epidemiological patterns of varicella outbreaks in Daegu and Gyeongsangbuk-do from 2022 to 2025.
Methods
Varicella outbreaks reported through the Korea Disease Control and Prevention Agency surveillance system in Daegu and Gyeongsangbuk-do from January 2022 through December 2025 were analyzed. Of the 235 reported outbreaks, 213 met the inclusion criteria after excluding reclassified, duplicate, deleted, and out-of-region outbreaks. Outbreak size and duration were analyzed for 209 outbreaks involving 2,253 outbreak-associated cases with available case-level information.
Results
The number of varicella outbreaks increased from 14 in 2022 to 84 in 2024, and outbreak-associated cases also peaked in 2024, at 898. Elementary schools accounted for 59.6% of outbreaks, and most outbreaks involving 11 or more cases occurred in elementary schools. Outbreak size did not differ significantly across years, whereas outbreak duration differed significantly across years.