Disability-adjusted life years of clonorchiasis in China: a high-resolution spatial analysis

Clonorchiasis is caused by the ingestion of raw freshwater fish containing infective metacercariae of Clonorchis sinensis. This study aimed to fully evaluate disease burden in terms of disability-adjusted life years (DALYs) for clonorchiasis in China.

Following our previous study which established the fine-scale prevalence distribution of C. sinensis infection in China, we further adopted Bayesian geostatistical models to estimate the infection intensity in terms of eggs per gram of feces (EPG) in infected individuals based on the national surveillance data of clonorchiasis between 2016 and 2021. Disability weight was then captured through its quantitative association with EPG, and used to estimate years of life living with a disability (YLDs). Incidence of cholangiocarcinoma attributed to C. sinensis infection was employed to calculate years of life lost (YLLs). DALYs was then estimated at 5 × 5 km² resolution, and aggregated by areas and populations.

In 2020, 431,009 [95% Bayesian credible interval (BCI): 370,427 to 500,553] DALYs were exerted due to clonorchiasis in China, of which 372,918 (95% BCI: 318,775-435,727) was due to YLDs and 57,998 (95% BCI: 50,816-66,069) due to YLLs. The DALYs, YLDs and YLLs per 1000 were 0.31 (95% BCI: 0.26-0.35), 0.26 (95% BCI: 0.23-0.31), and 0.04 (95% BCI: 0.04-0.05), respectively. The DALYs predominantly distributed in southern areas including Guangxi (201,029, 95% BCI: 157,589-248,287) and Guangdong (161,958, 95% BCI: 128,326-211,358). The DALYs was over doubled in male (302,678, 95% BCI: 262,028-348,300) than in female (127,970, 95% BCI: 106,834-151,699), and high in middle aged population.

Clonorchiasis causes significant disease burden in China especially in southern areas including Guangxi and Guangdong. Urgent control is needed for clonorchiasis in the endemic areas with high burden, and adult males need to be prioritized.