# Analysis and forecast of the disease burden of trachoma in China and the Global Population over 15 years of age, 1990–2021

## TL;DR

This study analyzes the decline in trachoma burden in China and globally from 1990 to 2021 and forecasts future trends, emphasizing the need for continued prevention efforts.

## Contribution

The study introduces a Bayesian Age-Period-Cohort model to project trachoma trends in China over the next 15 years.

## Key findings

- Trachoma prevalence and DALYs in China have consistently declined from 1990 to 2021.
- Elderly populations in China show the highest trachoma burden, with women affected more than men.
- Low-SDI regions globally experience the highest trachoma burden, while high-SDI regions show the lowest.

## Abstract

Trachoma is primarily transmitted through direct contact, and its complications—such as trichiasis and corneal opacity—significantly impair patients’ quality of life and result in substantial productivity losses. This study explores the differences in disability-adjusted life years (DALYs) and prevalence of trachoma globally, across regions with varying Socio-demographic Index (SDI) levels, and in China, while also projecting future trends specific to China.

This study, based on data from the Global Burden of Disease (GBD) database, utilized Joinpoint regression to analyze temporal trends in the age-standardized prevalence rate (ASPR) of trachoma in China from 1990 to 2021. The age-period-cohort (APC) model is used to estimate the net effects of age, period, and cohort on disease burden. Through decomposition analysis, the impact of aging, population growth, and epidemiological changes on trachoma disease burden is explored. In addition, the Bayesian Age-Period-Cohort (BAPC) model was used to project trends in the disability-adjusted life years (DALYs) rate and prevalence over the next 15 years, offering valuable insights for optimizing prevention and control strategies and consolidating achievements in disease elimination.

From 1990 to 2021, the ASPR and ASDR of trachoma exhibited a consistent downward trend in China, globally, and across regions with varying SDI levels. In 2021, the crude prevalence and crude DALYs rates of trachoma in China increased with age, reaching their peak in the 70–74-year age group. Marked disparities were observed among different SDI regions, with high-SDI areas recording the lowest prevalence and DALYs burden, while low-SDI regions experienced the highest. It is expected that from 2022 to 2036, the ASPR and ASDR of male and female populations aged 15 and above in China will both show a downward trend and continue to approach 0.

The continuous decline in the burden of trachoma disease in China from 1990 to 2021 indicates significant achievements in trachoma prevention and treatment. However, attention still needs to be paid to the elderly population aged 60 and above, and health education for the entire population should be strengthened to reduce the disease burden caused by trachoma in China.

By analyzing the prevalence and DALYs associated with trachoma across China, the global population, and five distinct SDI regions, this study found a marked decline in both prevalence and DALYs over time. These findings suggest that the implementation of the World Health Organization’s recommended SAFE strategy has achieved substantial progress toward the elimination of trachoma. The rate of decline in China was notably faster than in other regions, with middle- and low-SDI regions also experiencing more pronounced reductions. In addition, In addition, a comparison was made between the gender, age group, and the number of cases and DALYs of trachoma patients in China and global. It was found that the number of trachoma cases and DALYs in China increased with age, and the number of cases and DALYs in women of all age groups during the same period was higher than that in men. Although the prevalence of trachoma in China is continuously decreasing, as an infectious eye disease, there are still sporadic cases of trachoma, and small-scale outbreaks may occur again in areas with poor sanitation and economic backwardness. It is still necessary to continue to popularize trachoma prevention and control knowledge and prevent the recurrence of trachoma outbreaks.