2. Introduction
Meningitis is a relatively rare infection
that affects the delicate membranes called
meninges that cover the brain and spinal cord.
Meningitis used to occur most commonly in
infants, but because a vaccine is now given to
infants, this infection now occurs mainly in
adults. Outbreaks of meningitis, particularly
the bacterial form, are rare in the United
States. However, since 1991 such outbreaks
have been increasing for reasons not yet
understood. Viral meningitis tends to be less
severe, and most people recover completely.
Fungal meningitis is the most rare form and
generally occurs only in people with weak
immune systems, such as people with AIDS.
