Viral meningitis is the commonest form of meningitis.
It is an aseptic meningitis.
It is most common in young children.
Causes include:
- Enteroviruses – coxsackie A and B, echoviruses, polioviruses – 46% of cases
- Herpes simplex virus type 2 – 31%
- Varicella zoster virus – 11%
- Herpes simplex virus type 1 – 4%
- HIV
- Epstein-Barr virus
- Mumps virus
- CMV – consider in immunocompromised host
- West Nile virus – consider if there is a history of travel and acute distal weakness
- Lymphocytic choriomeningitis virus – consider if there has been contact with rodent droppings or urine
Investigation
- CSF analysis
- WCC 50-1000 x 106 cells/l
- Lymphocytosis (but there may be a neutrophilia in early disease)
- CSF:serum glucose >0.5 (=normal) – but may be low in mumps and lymphocytic choriomeningitis viral infection
- Protein 0.4-0.8g/l
- CSF PCR
Management
- Supportive
- Generally self-limiting
Small print gems:
HSV-2 meningitis reccurs in 20-50% of cases
Enteroviral meningitis peaks in the summer months
References
