Clinical outcomes of chikungunya across age groups: A systematic review

Chikungunya, caused by a mosquito-borne alphavirus, has emerged as a major public health concern due to its expanding geographical range and debilitating health outcomes in affected populations. Although research on chikungunya is growing, variations in the clinical presentation between age groups remain poorly understood. Understanding these variations is crucial for appropriate diagnoses, treatments, and timely prevention efforts. Therefore, this study aims to assess the clinical presentation of chikungunya across age groups and identify age-related differences and similarities.

We conducted a systematic literature review (17-09-2024) using Embase, MEDLINE, and gray literature, including a risk of bias assessment (Downs and Black, National Institute of Health). Results were descriptively presented. A total of 101 studies reported clinical outcomes in three age groups: children (<18 years), adults (18-64 years), and the elderly (≥65 years), with fourteen directly comparing age groups. The findings highlight substantial differences in disease presentation. Hospitalization and mortality rates were highest among the elderly and younger children, while faster recovery was reported for older children compared to other age groups. Symptom presentation also varied by age, with rash and headache being more common in adolescents and adults than in younger children and the elderly. Fever was more prevalent among adults and the elderly compared with children. Arthralgia was less commonly reported in children and the elderly than in adults, warranting attention for potential misdiagnosis due to atypical disease presentation. Lastly, the occurrence of chronic chikungunya symptoms appears to increase with age. Yet, the heterogeneity in reporting and scarcity of articles describing clinical features of children and the elderly limit definitive conclusions.

Our findings highlight the age-related variations in chikungunya disease presentation, reinforcing the need for tailored diagnostics, clinical management, and prevention strategies in all age groups. By identifying these differences, our study helps guide future research and public health policies aimed at reducing the impact of chikungunya worldwide.