Subacute sclerosing panencephalitis incidence following measles elimination efforts in the Republic of Korea.

Abstract

Objectives: Subacute sclerosing panencephalitis (SSPE) is a rare but fatal neurodegenerative disease caused by persistent measles virus infection. After a significant measles outbreak in 2000-2001, the Republic of Korea implemented a nationwide measles elimination program, which led to a dramatic reduction in measles incidence. This study aimed to evaluate the impact of these measles elimination efforts on the incidence of SSPE in the Republic of Korea.

Methods: This nationwide, population-based retrospective cohort study identified patients newly diagnosed with measles and SSPE between 2007 and 2022, registered in the Health Insurance Review and Assessment Service (HIRA) and Korea Disease Control and Prevention Agency (KDCA) databases. Population-based incidence rates of measles and SSPE were calculated and compared annually.

Results: A total of 236 measles cases (HIRA data) and 1,168 measles cases (KDCA data), along with 2,736 SSPE cases, were diagnosed during the study period. Measles incidence significantly declined, reaching zero cases in 2021, while SSPE incidence displayed an upward trend, peaking in 2014. The mean age at SSPE onset was 21.2 years, with a marked male-to-female ratio of 13.0:1.

Conclusion: SSPE incidence was remarkably low in the post-outbreak period, likely attributable to successful measles control. This study underscores the critical importance of maintaining low measles incidence through sustained vaccination efforts, preventing SSPE and other measles-related complications.