NAME OF DISEASE: Viral meningitis
ETIOLOGICAL AGENTS: Mumps virus
Coxsackie B virus
Human Herpesvirus 1 (Herpes simplex 1 virus)
Lymphocytic choriomeningitis viruses-Arenavirus
Louping ill virus
Pseudolymphocytic meningitis virus
Coxsackie A virus
The virus enters the body at various sites, depending on the species of the organism. Viral replication occurs at these regional sites which gives rise to a primary viremia. Target organs outside the CNS are infected as a consequence of this primary viremia. Further replication results in a secondary viremia and passage of the virus to the CNS, where it penetrates susceptible cells and replicates.
Penetration of either the blood-CSF or the blood-brain barrier may be accomplished by means of virus-laden phagocytes migrating through blood vessels of the meninges or brain or by passage of virus particles through the choroid plexus or other areas of preferential permeability. There is always some involvement of brain tissue so the disease is really a meningoencephalitis. There are few autopsy reports of patients with uncomplicated viral meningitis as the disease is generally milder than bacterial or fungal meningitis and is self limiting.
The signs and symptoms of viral meningitis are variable. They may include:
1. Sudden onset
2. Intense frontal or retro-orbital headache
3. Undulating fever that never goes above 104°F
4. Skin rash
At the onset of fever or shortly thereafter there is:
7. Sore throat
There may also be (but not commonly):
12. Tinnitus (noise in the ears)
14. Chest and abdominal pain
15. Paresthesia (abnormal sensation)
Nuchal rigidity develops and there are almost always stiffness of the back and pain on flexion. The Kernig and Brudzinski signs may or may not be elicited. Leukocyte count is normal. The CSF is transparent to slightly turbid (<500 leukocytes/mm3), glucose is normal but protein is elevated. Diagnosis requires virus isolation and serological techniques.
Viral meningitis may be confused with:
1. Bacterial meningitis
7. Lymphogranuloma venereum
9. Mycoplasmal pneumonia
11. Cat-scratch disease
Full recovery with no sequelae
Bed rest, analgesic drugs, repletion and conservation of fluids and electrolytes.