Trends and Age-Period-Cohort Effect on Incidence of Varicella Under Age 35 - China, 2005-2021.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: Varicella is an acute respiratory infectious disease primarily affecting children. However, recent studies have indicated an increasing susceptibility to varicella among older age groups.

WHAT IS ADDED BY THIS REPORT?: The findings demonstrate a significant rise in the incidence rate among individuals aged 15-19. Males under 20 years old were found to have a higher risk compared to females, whereas males had a lower risk compared to females aged 20-35 years.

WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: This study is the first comparative analysis using varicella data reported between 2005 and 2021 to examine the contributions of age, period, and birth cohort to varicella incidence in China. This study aims to provide a comprehensive analysis of the epidemiological characteristics of varicella in China and identify high-risk groups. The results of this study will contribute valuable information for the development of varicella prevention policies.