A Profile Study of Japanese Encephalitis in an Industrial Hospital in Eastern India

Introduction Japanese encephalitis (JE), caused by a Flavivirus, is one of the common causes of mosquito-borne encephalitis the world over including India. The disease is endemic in many states of India, including Jharkhand. Mortality ranges from 30 to 40% in different studies and a large number of patients survive with permanent neuropsychiatric sequelae. Aim The study aimed to evaluate the clinical spectrum, laboratory (including radiological) features and outcomes of cases of JE admitted in our hospital. Methods and materials This is a retrospective observational study consisting of confirmed cases of JE admitted to the medical wards and critical care unit of Tata Main Hospital (TMH) from January to December 2022. The case records of patients were retrieved from Hospital Management System (HMS) and analysed for demographic characteristics, clinical presentations and treatment details along with outcome measures, which included length of stay (LOS), complications, and mortality. Observation Of the 14 confirmed cases, six (43.9%) were males and eight (57.1%) were females. The average age of male and female patients was 41.8 ± 23.1 and 35.1 ± 20.5 years respectively. A total of 35.7% of the patients were in the age group of 21 to 30 years. The clinical manifestations in the decreasing frequency were altered sensorium in 11 (78.6%) patients, headache in six (42.8%) patients, generalised convulsions in four (28.6%) cases, vomiting in three (21.4%) cases and weakness in all limbs and of the right half of the body in one (7.1%) case each. Objective neurological findings noted were neck stiffness (3, 21.4%), cog-wheel rigidity (3, 21.4%), tremors (2, 14.3%), delirium (2,14.3%), quadriparesis, facio-brachial dystonia and hemiparesis (1, 7.14%) patient each. Neutrophilic leucocytosis was observed in five (35.7%) patients and mild thrombocytopenia in two (14.3%) patients. The average C-reactive protein (CRP) level was 7.3 ± 6.6 mg/dL. Three (21.4%) patients had mild transaminitis. Cerebrospinal fluid analysis was abnormal in all patients with varying degrees of elevated protein and cell count, while adenosine deaminase (ADA) levels and sugar were normal in all patients. Magnetic resonance imaging (MRI) brain revealed bilateral thalamic T2 FLAIR (fluid-attenuated inversion recovery) hyperintensities in 11 patients (78.6%). The average length of hospital stay was 9.6 ± 4.7 days. Ten patients (71.4%) needed treatment in the critical care unit. Complications seen were acute respiratory distress syndrome (2, 14.3%), sepsis with multiorgan failure (2, 14.3%) and ventilator-associated pneumonia (1, 7.1%). The case fatality rate was one (7.1%). Six patients (42.9%) had residual neuropsychiatric sequelae. Conclusion JE continues to be a major health-related problem. Most cases are concentrated during the post-monsoon period, coinciding with a higher vector density. Patients from rural backgrounds were seen to be more susceptible. JE may present with varying severities of acute encephalitic syndrome. As there is no specific treatment, timely diagnosis is important to reduce the morbidity and mortality associated with this disease. Clinicians must be aware of the wide spectrum of presentation of this disease. A high degree of suspicion along with thorough clinical examination and appropriate investigations are needed to diagnose this condition early and prevent complications.