Long-term Chikungunya Sequelae in Curaçao: Burden, determinants, and a novel classification tool

Background: Beyond the acute illness phase, chikungunya constitutes a public health problem given its chronic disease phase, which may include long-term arthralgia, arthritis, fatigue, and depression. Currently, there is no consensus on how to define chikungunya chronicity. Methods: A comprehensive cross-sectional survey was performed in Curaçao in June and July 2015 to evaluate 304 adult laboratory-confirmed chikungunya patients 3-16 months after diagnosis. We developed a novel tool, the Curaçao Long-Term Chikungunya Sequelae (CLTCS) score, to classify chronic chikungunya disease and estimate its burden regarding disease duration, clinical presentation, and impact on quality of life. Results: Disease persistence was estimated to be 79% one month after symptom onset and 64% after 400 days. Chikungunya persistence was characterized by higher proportions of arthralgia, weakness, myalgia, and age 41-60 years. Individuals were classified as "highly affected," "mildly affected," and "recovered." "Highly affected" disease status was associated with clinical complaints (arthralgia, weakness, loss of vitality, and being diabetic) and major decreases in quality-of-life scores. Conclusions: In the Caribbean, a high proportion of chikungunya patients remains chronically affected. We propose the CLTCS as a suitable score to easily and rapidly classify the severity of chikungunya chronic disease and to assess the need for symptom-alleviating treatment.