Distinguishing Leptospirosis from Other Causes of Acute Encephalitis Syndrome: Clinical Insights

INTRODUCTION: Acute encephalitis syndrome (AES) is a serious public health problem in India, especially in Uttar Pradesh, where children and adolescents are particularly affected. Although viral diseases such as Japanese encephalitis (JE) are the main cause, many cases remain unexplained. AES could be caused by a zoonotic leptospirosis, but its role is uncertain. AIM: The aim is to assess the prevalence and clinical features of leptospirosis in children with AES in a tertiary care hospital and compare the etiology with other causes. MATERIALS AND METHODS: Children aged 1-14 years with AES or AFI were included. Comprehensive clinical assessments, laboratory investigations and etiologic testing for leptospirosis (immunoglobulin M enzyme-linked immunosorbent assay, polymerase chain reaction and microscopic agglutination test) and other diseases (JE, scrub typhus, dengue, chikungunya) were performed. Comparative and descriptive statistics were used. RESULTS: 62% of the 100 AES patients were male, with a mean age of 75.4 ± 35.7 months. They mostly lived in rural areas (59%) and were poor (85%). Hepatosplenomegaly (53%, 23%), seizures (91%), and mental retardation (90%) were prevalent. Laboratory results showed anemia, leukocytosis, thrombocytopenia, and elevated aspartate transaminase/alanine transaminase. High protein and cell counts were found in the cerebrospinal fluid. The mortality rate was 14%. JE (20%) was the most common, followed by scrub typhus (16%) and dengue (14%), while 44% were undiagnosed. CONCLUSION: JE, scrub typhus, and dengue encephalopathy cause most AES in Uttar Pradesh. Leptospirosis, a rare disease, should be investigated in the differential diagnosis, especially with multisystem involvement and environmental risk factors. Early leptospirosis diagnosis and treatment improve outcomes.