A 32-year-old woman from Mumbai presents with a 3-day history of fever, headache, myalgias, and mild neck stiffness. On examination, she is alert, afebrile now (given paracetamol), with no rash. CSF analysis shows: WBC 120/μL (90% lymphocytes), protein 60 mg/dL, glucose 55 mg/dL (serum glucose 100 mg/dL), Gram stain and bacterial culture are negative. PCR for enterovirus is positive. She is otherwise hemodynamically stable. What is the most appropriate management?

Explanation

## Clinical Diagnosis This is a case of **viral meningitis** (aseptic meningitis) caused by **enterovirus**, confirmed by positive PCR. ### CSF Profile: Viral vs. Bacterial | Feature | Viral Meningitis | Bacterial Meningitis | |---------|------------------|---------------------| | **Cell count** | 10–500/μL (typically <300) | 100–10,000/μL (often >500) | | **Predominant cell** | Lymphocytes (early: neutrophils) | Neutrophils (>80%) | | **Protein** | 40–100 mg/dL (mild elevation) | >100 mg/dL (marked elevation) | | **Glucose** | Normal to mildly low (CSF:serum >0.4) | Low (CSF:serum <0.4) | | **Gram stain** | Negative | Often positive | | **Culture** | Negative (viral PCR positive) | Positive (bacterial culture) | | **Clinical course** | Benign, self-limiting | Fulminant, high mortality | ### Key Features in This Case **High-Yield:** This patient has **viral meningitis** because: 1. **Lymphocytic predominance** (90%) — hallmark of viral meningitis. 2. **Negative Gram stain and culture** — rules out bacterial meningitis. 3. **Positive enterovirus PCR** — confirms viral etiology. 4. **Mild CSF abnormalities** — protein only 60 mg/dL, glucose mildly low but CSF:serum ratio ~0.55 (>0.4). 5. **Hemodynamically stable, no rash** — no signs of severe systemic infection. 6. **Self-limited course** — enteroviral meningitis is typically benign. ### Management of Viral Meningitis **Key Point:** Viral meningitis is self-limited and does NOT require antibiotics or antivirals in immunocompetent patients. **Management strategy:** 1. **Supportive care** — the cornerstone of treatment. - IV fluids for hydration. - Analgesia (paracetamol, NSAIDs) for headache and myalgias. - Rest and observation. 2. **Avoid antibiotics** — no benefit in viral meningitis; unnecessary exposure to side effects and resistance. 3. **Avoid acyclovir** — enteroviral meningitis does NOT respond to acyclovir (it is active only against HSV and VZV). 4. **Discharge criteria** — after 24–48 hours if: - Clinically improving (fever resolved, headache improving). - Able to tolerate oral intake. - No signs of complications (encephalitis, ventriculitis). - Reliable follow-up available. **Clinical Pearl:** Enteroviral meningitis is the most common cause of aseptic meningitis in summer and autumn in tropical countries like India. Prognosis is excellent; most patients recover fully within 1–2 weeks without sequelae. **Mnemonic:** **VIRAL** — **V**iral meningitis needs **I**V fluids, **R**est, **A**nalgesia, **L**ymphocytic CSF. [cite:Harrison 21e Ch 381]