Rheumatic-musculoskeletal pain and disorders in a naïve group of individuals 15 months following a Chikungunya viral epidemic in south India: a population based observational study

BACKGROUND: Prospective community data on arthropathy following Chikungunya (CHIKV), a self-limiting, arboviral infection, causing debilitating arthropathy are lacking. The clinical profile of chronic rheumatic-musculoskeletal (RMSK) pain and disorders, captured inadvertently about 15 months following a CHIKV epidemic is described. MATERIALS AND METHODS: Patients with RMSK pain following the CHIKV epidemic in 2007 were identified from a randomly selected population of 5277 (Age > 15 years) in a village in south India, using a validated questionnaire-based house-to-house survey. Typical narration, records and serology were relied upon to classify CHIKV. Respondents who recorded active pain sites on a human mannequin were evaluated by Rheumatology physicians. RESULTS: A total of 1396 CHIKV infected individuals with painful MSKD were identified, of whom 437 patients (mean age: 48.37 ± 13.62 years; 71.6% women) who were naïve to RMSK pain prior to the epidemic were studied in detail. Incidence of RMSK pain and disorders in the naïve group was 8.3% (437/5277). Knee was the commonest self-reported pain site (83.3%). Majority of the patients (57%) had postviral non-specific polyarthralgia. Soft tissue rheumatism was very common (27.7%). Rheumatoid arthritis and seronegative spondyloarthritis were observed in 6 and 11 patients, respectively. CONCLUSIONS: Although a causal association could not be established, this study has unravelled a wide spectrum of unrecognised post-CHIKV chronic RMSK disorders. Aetiopathogenesis and risk factors of chronicity need to be studied further.