Clinical Profile of Chikungunya Patients during the Epidemic of 2007 in Kerala, India

BACKGROUND: The association of the present Chikungunya pandemic with a mutation in the Chik virus is already established in many parts of the world, including Kerala. Kerala was one of the worst-affected states of India in the Chikungunya epidemic of 2006–2007. It is important to discuss the clinical features of patients affected by Chikungunya fever in the context of this change in the epidemiology of the disease. AIM: This study tries to analyze the clinical picture of the Chikungunya patients in Kerala during the epidemic of 2007. SETTING AND DESIGN: A cross-sectional survey was carried out in five of the most affected districts in Kerala, India. MATERIALS AND METHODS: A two-stage cluster sampling technique was used to collect the information. Ten clusters each were selected from all the five districts, and the size of the clusters were 18 houses each. A structured interview schedule was used for data collection. Diagnosis based on clinical signs and symptoms was the major case-finding strategy. RESULTS AND CONCLUSION: Of the 3623 residents in the surveyed households, 1913 (52.8%) had Chikungunya clinically. Most of the affected were in the adult age group (73.4%). Swelling of the joints was seen in 69.9% of the patients, followed by headache (64.1%) and itching (50.3%). The knee joint was the most common joint affected (52%). The number of patients with persistence of any of the symptoms even after 1 month of illness was 1388 (72.6%). Taking bed rest till the relief of joint pain was found to be a protective factor for the persistence of the symptoms. Recurrence of symptoms with a period of disease-free interval was complained by 669 (35.0%) people. Older age (>40 years), a presentation of high-grade fever with shivering, involvement of the small joints of the hand, presence of rashes or joint swelling during the first week of fever and fever lasting for more than 1 week were the significant risk factors for recurrence of symptoms predicted by a binary logistic regression model. In conclusion, we found that there is substantial acute and chronic morbidity associated with the Chikungunya epidemic of 2007.