Age-group differential trends in the incidence of herpes zoster during 2010–2024 using Korean national healthcare claim data

Herpes zoster (HZ) results from reactivation of the latent varicella-zoster virus, typically in immunologically weakened adults. Relatively few studies have examined recent trends in the incidence of HZ in Korean populations, including children. Korean national healthcare claim data from 2010 to 2024 were utilized for analyses. HZ incident patients were annually defined as those with the International Classification of Diseases, 10th revision code for HZ. In each year, HZ incidence was estimated using national population statistics. HZ incidence increased from about 10 to 15 per 1,000 people between 2010 and 2024 in Korean populations. However, its pattern substantially varied by age-group: rapidly increased until 2013, but afterward substantially attenuated among adults aged ≥50 y; steadily increased among adults aged 30-40 y; incrementally decreased in children aged 5-19 y; but rapidly increased after 2018 in children aged 0-4 y. HZ incidence in Korean populations increased during 2010-2024 with distinct age-group differential patterns. The recent uprising in HZ incidence among the children aged 0-4 y warrants urgent investigations.