Background/Purpose:

Chikungunya fever (CHIK) has joint involvement as a striking characteristic, which may persist for months. This study aimed to better understand the clinical impact of this new disease, evaluating the patients of a reference center for infectious disease (Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation – FIOCRUZ) in Brazil during the 2016 CHIK outbreak.

Methods:

From April 2016 to October 2016, patients who sought care at the FIOCRUZ’s Acute Febrile Disease Outpatient Clinic, with symptoms suggestive of CHIK (fever, musculoskeletal pain) were evaluated by a team of infectologists and rheumatologists through medical history, physical exam, clinical questionnaires and diagnostic lab tests. Patients were stratified by symptoms duration at first evaluation, classified as acute if symptoms present for ≤14 days and subacute/chronic if symptoms present for >14 days. After about 1 year from the initial visit, we contacted the patients by phone to obtain information about the current clinical status regarding joint pain, swelling and morning stiffness.

Results:
We evaluated 61 patients with suspected CHIK. Diagnosis was confirmed in 41 patients by serology or PCR; in 20 patients, lab results were not available. Demographic and clinical characteristics of patients with diagnostic confirmation were similar compared to those without lab results; thus, both groups were analyzed together. There were 36 women and 25 men; none had autoimmune disease. In 18 patients, extra-articular manifestations (bursitis, tenosynovitis and carpal tunnel syndrome) were described. Baseline characteristics are shown in Table.

At 1 year, we managed to contact 30 patients; 9 of them referred symptoms resolution and 11 presented partial improvement, while 10 patients reported pain level similar to the initial presentation. Most patients had peripheral involvement, mainly hands and feet. Pain was considered mild in 9 patients, moderate in 9 patients, and intense in 3 patients. Subjects who chronically persisted with similar symptoms had significantly higher mean HAQ-DI at baseline (HAQ-DI = 2.4, 95% confidence interval (CI) 2.0–2.8) than those who achieved partial improvement or symptoms resolution (HAQ-DI = 1.5, 95% CI 1.1–2.0, p=0.01). 

Conclusion:

Our study showed that CHIK results in dramatic, and often chronic joint involvement, with severe pain, fatigue and functional disability. Furthermore, the baseline HAQ-DI may predict chronicity of symptoms, although our conclusions are limited by our sample size.