Epstein-Barr Virus-positive Diffuse Large B-cell Lymphoma Presenting as Pyrexia of Unknown Origin Complicated by Paraneoplastic Neurological Syndrome.

Chikungunya virus (CHIKV) infection is an arboviral disease transmitted by Aedes mosquitoes, typically presenting with fever, rash, and polyarthralgia. Neurological complications such as meningitis are rare and more often seen in neonates and immunocompromised individuals. Hepatic involvement is also uncommon, with only a few reports describing significant hepatitis in the absence of other risk factors. We report the case of a 68-year-old male, previously healthy with no comorbidities, who presented with acute febrile illness followed by severe headache, neck stiffness, and altered sensorium. Laboratory investigations revealed elevated transaminases, and cerebrospinal fluid analysis was consistent with viral meningitis. Serology confirmed CHIKV infection (immunoglobulin M enzyme-linked immunosorbent assay positive). Neuroimaging was unremarkable. The patient was managed with supportive care, intravenous fluids, and close neurological monitoring. Liver function normalized gradually over 2 weeks, and neurological recovery was complete by discharge. This case highlights the rare dual presentation of Chikungunya meningitis and hepatitis in an elderly patient without underlying comorbidities, underscoring the need for clinicians in endemic areas to consider CHIKV in the differential diagnosis of viral meningitis with hepatic dysfunction.