“A Rare Presentation of Mumps Encephalitis in a Child with Missed MMR Vaccination: A Case-Based Insight”

Abstract

This case report describes an uncommon presentation of mumps meningoencephalitis in a 7-year-old malnourished child who had not completed the MMR vaccination schedule, having missed the second dose. The child developed high-grade fever, persistent headache, vomiting, neck stiffness, and parotid swelling after recent exposure to an infected sibling. Clinical evaluation showed no focal neurological deficits, and initial investigations including a normal noncontrast brain CT and CSF analysis pointed toward viral etiology, with lymphocytic predominance, normal glucose, and mildly elevated protein. Multiplex PCR of CSF confirmed mumps virus and ruled out herpes simplex and enterovirus. Empirical intravenous acyclovir and ceftriaxone were initiated and later withdrawn upon confirmation of the viral cause. Supportive management with fluids and antipyretics led to progressive improvement, and the child recovered fully without neurological complications. This case underlines the need to consider mumps in pediatric encephalitis cases involving parotid swelling and incomplete immunization, while also stressing the diagnostic value of CSF PCR. Moreover, it highlights how inadequate vaccination and poor nutritional status can contribute to the severity of preventable viral CNS infections, reinforcing the necessity of timely immunization and proper nutrition in children.