Viral Meningitis: Causes, Symptoms, and Why Most Cases Recover Fully

Meningitis — inflammation of the meninges (the membranes covering the brain and spinal cord) — is classified by aetiology into viral, bacterial, fungal, and tubercular. Viral meningitis (also called aseptic meningitis) is the most common form, accounting for the majority of meningitis cases in immunocompetent people. Unlike bacterial meningitis, which has a mortality of 15–25% even with treatment, viral meningitis is generally self-limiting and benign — most patients recover completely within 7–14 days without specific treatment.

Causes and Epidemiology

Enteroviruses (Coxsackievirus, Echovirus, Enterovirus 71) cause approximately 80–85% of viral meningitis — most cases occur in summer and autumn when enteroviruses circulate. Other causes: herpes simplex virus (HSV-2 most commonly — genital herpes primary infection or reactivation; unlike HSV-1 encephalitis, HSV-2 meningitis is benign); mumps (rare with vaccination); varicella-zoster virus; HIV (primary infection with acute meningitis); Epstein-Barr virus; arboviruses (dengue, West Nile).

Clinical Features

Fever, severe headache (typically diffuse, worsened by light and sound), neck stiffness (meningism), and photophobia — the cardinal features. Unlike bacterial meningitis: onset is typically less abrupt (over 1–3 days rather than hours); consciousness is usually preserved; rash (petechial/purpuric) is absent (the purpuric rash is specific to meningococcal bacterial meningitis); the patient is uncomfortable but not critically ill.

CSF Findings — The Lumbar Puncture

LP is essential to distinguish from bacterial meningitis: lymphocytic pleocytosis (100–1000 cells, predominantly lymphocytes); protein mildly elevated (50–100mg/dL); glucose normal (CSF:serum ratio above 0.6); Gram stain and bacterial culture negative; viral PCR (enterovirus, HSV) positive. Treatment: supportive — rest, analgesia, antipyretics, adequate hydration. Acyclovir if HSV cannot be excluded. Hospital admission is appropriate until bacterial meningitis is excluded. Sri Anand CNC, Chanda Nagar, Hyderabad. Call +91 90633 66983.