Trends and Projections of Varicella and Herpes Zoster Disease Burden Among Individuals Aged 50 Years and Older in China, 1990–2021

Objective To analyze the trends in the disease burden of varicella and herpes zoster among individuals aged ≥50 years in China from 1990 to 2021 and project future trends, providing evidence for varicella and herpes zoster prevention and control. ‌Methods Data on the incidence, prevalence, mortality, and disability-adjusted life years (DALYs) of varicella and herpes zoster among individuals aged 50 years and older in China and globally were extracted from the Global Burden of Disease (GBD) 2021 database. Comparisons were made between 2021 and the baseline year (1990) for these indicators. Joinpoint regression models were employed to dynamically analyze trends in disease burden. Decomposition analysis was conducted to identify key drivers of burden changes. Additionally, the Bayesian Age-Period-Cohort (BAPC) prediction model was utilized to fit age-standardized rates and forecast trends from 2022 to 2035. ‌Results In 2021, the age-standardized incidence rate (ASIR) of varicella and herpes zoster among the Chinese population aged 50 years and older was 726.99 per 100,000, showing a 0.01% increase compared to 1990. The age-standardized prevalence rate (ASPR), mortality rate (ASMR), and DALY rate (ASDR) were 134.09 per 100,000, 0.14 per 100,000, and 8.94 per 100,000, respectively, representing reductions of 0.08%, 88.54%, and 61.42% from 1990 levels. Females consistently exhibited higher disease burden than males. Joinpoint regression analysis revealed that ASIR and ASPR exhibited a significant upward trend during 2000–2005, followed by a sharp decline in 2005–2010, with greater fluctuations observed in females compared to males. In contrast, ASMR and ASDR demonstrated sustained downward trends. Global trends paralleled those observed in China. Population growth was identified as the primary driver of disease burden changes in both China and globally. Projection modeling predicted that by 2035, China's ASIR, ASPR, ASMR, and ASDR may reach 728.77 per 100,000, 145.62 per 100,000, 0.08 per 100,000, and 8.91 per 100,000, respectively. Notably, ASIR and ASPR are projected to exceed global levels, while ASMR and ASDR are anticipated to remain below global averages. ‌Conclusion varicella and herpes zoster imposes a higher incidence and prevalence burden among individuals aged 50 years and older in China compared to global levels, with a projected sustained increasing trend. The disease burden is consistently greater in females than in males, underscoring the urgent need for targeted interventions to mitigate its escalating impact.