What is meningitis?

Meningitis is an infection that causes inflammation of the membranes (the meninges) covering the brain and spinal cord.

Bacterial meningitis is a true medical emergency that may result in death or brain injury even if treated. Bacterial strains that cause meningitis include Streptococcus pneumoniae, Haemophilus influenza, Neisseria meningitides (meningococcus), Listeria monocytogenes and many other types of bacteria.

Viral meningitis is usually not serious, and symptoms should disappear within a few weeks. It usually develops in the late summer and early fall. Seventy percent of the infections occur in children under the age of five.

Symptoms   

• Fever and chills

• Severe headache

• Nausea and vomiting

• Stiff neck

• Sensitivity to light

• Mental status changes

• Bulging fontanelles (the soft spots in a baby's skull may bulge)

• Poor feeding or irritability in children

Diagnosis

Diagnosing meningitis may require:

• Lumbar puncture

• Gram stain and culture of cerebral spinal fluid (CSF)

• Chest X-ray to look for other sites of infection

• Head CT scan to look for hydrocephalus, abscess or deep swelling

Note: Because meningitis is an important cause of fever in newborns, a lumbar puncture is often done on newborns who have a fever of uncertain origin.

Treatment 

Acute bacterial meningitis requires immediate hospital-based treatment and antibiotics. Secondary symptoms such as brain swelling, shock and seizures will require other medications and intravenous fluids. Antibiotics are ineffective against viral meningitis — its symptoms should clear up in a few weeks.