Characterization of the clinical forms of chronic chikungunya: an observational cohort study in Rio de Janeiro

This study aimed to characterize the clinical presentation of acute and chronic chikungunya virus infection in Brazil and identify predictors of chronic chikungunya.

We conducted a prospective observational cohort study in the emergency department of Hospital Quinta D'Or, Rio de Janeiro, between March 2016 and May 2017. Adults with suspected chikungunya were tested by RT-PCR for chikungunya, dengue, and Zika viruses. Patients with laboratory-confirmed chikungunya were enrolled. Clinical and demographic data were collected at baseline. At 90 days (D90), participants completed telephone follow-up assessing persistent symptoms, pain, and quality of life. Chronic disease was defined as ongoing arthralgia or myalgia at D90.

Among 134 PCR-confirmed cases, 100 completed follow-up and 38% reported chronic manifestations. Female sex (adjusted odds ratio [OR] 2.56, 95% confidence interval [CI] 1.02-6.25) and increasing age (adjusted OR 1.04, 95% CI 1.01-1.07) were independently associated with chronic disease. Prostration and retro-orbital pain showed trends towards association. Chronic symptoms were associated with pain interference affecting mood, work, and sleep.

Over one-third of adults with laboratory-confirmed chikungunya experienced persistent symptoms at D90, with substantial functional impact. Early identification of patients at risk may support targeted follow-up and integration of long-term care into arboviral disease management.