Prevalence, Risk Factors, and Outcome of Chikungunya Encephalitis in Hospitalized Patients at a Tertiary Care Center in Gujarat, India, During the 2016 Outbreak

Background India has experienced 2 major chikungunya viral (CHIKV) fever outbreaks over the last decade, with reportedly higher mortality during the 2006 outbreak. Methods This was a retrospective observational study conducted at a tertiary care center over a period of 4 months involving 110 hospitalized patients confirmed with CHIKV fever during the 2016 outbreak. Data on the proportion of patients with CHIK viral encephalitis (CHIK VE) and possible attributable risk factors were obtained from a retrospective chart review and data analysis using SPSS. Results Of 110 patients with confirmed CHIKV fever, 16 (14.6%) developed CHIK VE; 62.5% of the hospitalized patients with CHIK VE were older than 60 years. Patients with CHIK VE presented late to the hospital (4.9 +/- 2.7 vs 2.9 +/- 1.5, respectively, P = 0.00031) as opposed to those without encephalitis; 87.5% patients in the CHIK VE group required intensive care unit admission and had a prolonged hospital stay (9.2 +/- 6.7 days vs 5.1 +/- 4.2 days; odds ratio, 0.034; P = 0.001) compared with those in the nonencephalitis group. Patients in the extreme age groups were more vulnerable to CHIK VE compared with adults aged between 30 and 60 years, without a statistically significant difference. There was no statistically significant difference in the mean absolute lymphocyte count, globulin levels, total leukocyte counts, and underlying comorbidities between the 2 groups. Overall mortality with CHIK VE was 18.75%. Conclusions Large-scale studies are needed to validate the association of CHIK VE patients with probable risk factors, as it is associated with high mortality, based on the findings of the present study.