Norovirus infections in China linked to CNY 20.23 billion annual medical cost

Norovirus was detected in 18.80% of patients with acute gastroenteritis who underwent testing at medical institutions in four Chinese provinces between 2018 and 2024, according to a multicenter retrospective study that also estimated the infection’s national direct medical cost at CNY 20.23 billion per year. The analysis included 23,527 patients and combined hospital data with national population census and epidemiological survey information for the burden estimate. The findings show substantial variation in positivity, complications and medical spending by age and care setting, but the hospital-tested sample does not represent every acute gastroenteritis episode in China.

The overall norovirus positivity rate was 18.80%, with a 95% confidence interval of 18.30% to 19.30%. Positivity was higher among inpatients, at 26.15% (95% CI 25.28% to 27.04%), than among outpatients, at 13.78% (95% CI 13.21% to 14.36%). Children younger than five years had the highest age-specific positivity rate, reaching 30.49% (95% CI 29.56% to 31.43%).

Logistic regression models were used to analyze factors associated with norovirus infection, hospitalization risk, complications and direct medical costs, but the supplied results do not identify the individual predictors or report which ones were statistically significant. Among norovirus-positive patients, 18.97% (95% CI 17.84% to 20.16%) had at least one potential complication occurring concurrently with their acute gastroenteritis. Dehydration was the most prevalent, recorded in 11.28% of positive patients (95% CI 10.39% to 12.25%), followed by convulsions in 5.52% (95% CI 4.88% to 6.23%).

The investigators described the clinical pattern as age-dependent: children younger than five tended to experience more severe manifestations, while patients aged 65 or older appeared to bear higher direct medical expenditure in the hospital-based sample. These were observational findings and do not establish that age itself caused differences in infection, severity or spending. Median direct medical costs differed sharply between inpatient and outpatient care.

The median cost for inpatients was CNY 4,580 per case, with an interquartile range of CNY 3,129 to CNY 6,402, compared with CNY 230 for outpatients, with an interquartile range of CNY 128 to CNY 354. Adults aged 65 or older had the highest per-capita direct medical cost: a median of CNY 5,322, with an interquartile range of CNY 2,411 to CNY 10,798. At the national level, the model estimated that children younger than five bore an aggregate medical burden 11.2 times that of people aged 60 or older.

The national annual direct medical cost of norovirus infection was estimated at CNY 20.23 billion by combining the multicenter study with national population census and epidemiological survey data. The estimate is subject to the representativeness of institutions in four provinces, the selection of patients who received norovirus testing and the assumptions used to extend hospital-based observations nationwide. The study also concerned acute gastroenteritis patients seeking medical consultation, and its age, regional and seasonal comparisons should not be interpreted as population-wide trends over time.

Within these limits, the results identify a heterogeneous burden: high positivity and more severe clinical manifestations among young children, higher per-patient expenditure among older adults and a substantial cost associated with hospital care. The authors concluded that age-targeted public health strategies and regionally tailored allocation of healthcare resources are needed to address these differences.

Subject of Research: Age variation, complications and direct medical costs of norovirus acute gastroenteritis in China

Article Title: Epidemiological features and direct medical costs of norovirus acute gastroenteritis in China

Article References: Du, J., Zeng, J., Hu, X.-W., Wang, Y.-M., Hu, Y., Jiang, L.-F., Sun, X.-J., Guo, H.-L., Huang, J., Long, T., Cui, F., & Lu, Q.-B. (2026). Epidemiological features and direct medical costs of norovirus acute gastroenteritis in China. BMC Infectious Diseases. https://doi.org/10.1186/s12879-026-14337-9

Image Credits: AI Generated

DOI: 10.1186/s12879-026-14337-9

Keywords: norovirus, acute gastroenteritis, China, direct medical costs, hospital epidemiology, children, older adults, dehydration, disease burden, retrospective study, Epidemiological, features