Age- and comorbidity-stratified clinical profiles of hospitalized chikungunya patients, China, 2025

OBJECTIVES: This study aimed to characterize the clinical profiles of patients hospitalized with chikungunya fever in Shunde, China (2025), and to use time-to-event analysis to identify predictors of prolonged viral clearance. METHODS: A retrospective cohort study included 1721 confirmed chikungunya patients from July to August 2025. Patients were stratified by age and comorbidities. Disease course was classified as regular (≤7 days) or prolonged (>7 days). Cox proportional hazards regression was used to identify factors independently associated with the time to viral RNA clearance. RESULTS: The cohort (mean age 43.6 ± 21.8 years) exhibited high frequencies of key symptoms: fever (88.4%), arthralgia (88.3%), and rash (71.4%). Clinical profiles differed significantly by age: pediatric cases (n = 276) had more prominent fever, whereas arthralgia duration increased and viral clearance slowed progressively from pediatric to adult to geriatric groups (mean clearance: pediatric 5.7 days vs geriatric 6.6 days, all P < 0.001). A prolonged disease course (>7 days) occurred in 13.7% of patients (n = 235/1721) and was independently associated with advanced age (hazard ratios [HR] = 0.994, P < 0.001) and ischemic encephalopathy (HR = 0.593, P = 0.038). Patients with comorbidities, especially diabetes, had more severe laboratory abnormalities and delay viral clearance. Higher baseline viral load was correlated with older age, specific comorbidities, and the presence of arthralgia. CONCLUSION: Age and comorbidities significantly influence chikungunya manifestations and outcomes, supporting early stratification and personalized management.