Meningococcal meningitis is an infection caused by a bacterium,
which causes inflammation of the membranes covering the brain
and spinal cord. Meningococcal disease is primarily an early childhood
infection, but also affects adolescents and adults. Meningococcal
infections occur worldwide. The causative organism, N. meningitidis
bacteria (Meningococcus), is normally found in the nasopharnyx
(throat) in about 5% of healthy individuals and does not cause
disease. The Meningococcus continues to be a leading cause of
bacterial meningitis and septicemia. It is cyclic, occuring yearly,
with occasional localized outbreaks.
The way N. meningitidis bacteria enter the body is through
the upper respiratory tract. People can acquire the disease by
inhaling the bacteria (when an infected person coughs on them,
for example), by direct mouth-to-mouth contact with an infected
person, or by indirect contact (for example, by touching one's
nose after touching an object or a hand that was recently contaminated
with an infected person's nasal secretions).
Symptoms and disease course
The majority of persons who become infected develop very mild
upper-respiratory symptoms or no symptoms at all. More serious
cases occur when the bacteria succeed in invading through surface
tissues and entering the bloodstream and/or other parts of the
body. This most often takes 1 of 3 forms, which may or may not
occur one after the other:
Symptoms appear suddenly and include fever, chills, headache,
body ache, nausea, vomiting, drowsiness, and a body rash that
at first may look like faint pink "rose spots" or hives
and later may develop into petechiae (tiny red dots that are pinprick
to pinhead size).
Symptoms again appear suddenly, but are much more intense
and can progress rapidly. The headache is severe and the chills
shaking. In cases where the bloodstream is heavily invaded, very
large, dark reddish-purple blotches appear as blood seeps out
of damaged vessels into the skin; circulatory collapse can occur.
In cases where the brain is invaded, the infected person may fall
into a coma.
While this is not the most common form of meningococcal infection,
it is the most classic. Meningitis occurs when the bacteria invade
the membranes lining the spinal cord and brain. The neck and spine
become rigid, and attempts to flex one's head backward and forward
are painful. The inflammation causes increased pressure, which
can result in severe headache, nausea, vomiting, dilated pupils
and, in severely ill infants, a bulging of the fontanelles (although
mildly ill infants may display only fever, vomiting, diarrhea
and irritability). Progression of the disease may result in delirium,
convulsions, coma and death.
This disease is world-wide. It is most common in poor, overcrowded
areas and seems to have a seasonal increase in winter and spring.
It can occur at any age, but it is most common in children younger
than 5 years; however, half of all cases occur in persons aged
2 years and older during epidemics. Older adults are also at increased
Meningococcal meningitis is the only form of bacterial meningitis
which causes epidemics. The largest epidemics of meningococcal
meningitis have been reported in sub-Saharan African countries
within the meningitis belt -- across the middle of Africa -- especially
during the December-June dry season, but epidemic meningococcal
disease can occur in any country regardless of climate.
Countries in sub-saharan Africa have experienced large outbreaks
every 8-12 years in the past, but intervals between major epidemics
have become shorter and more irregular since the beginning of
the 1980s. The possibility of a new epidemic cycle in the mid-1990s,
noted with outbreaks in 1995 (e.g. Cameroon, Niger), seems to
be confirmed by the outbreaks now reported in Burkina Faso and
Epidemics have also occured on an irregular basis in Burundi,
Kenya, Tanzania, northern India, Nepal and other countries. Large
outbreaks have been reported in Ethiopia and Brazil.
Travelers to any of these areas are at increased risk, especially
if they have prolonged or intimate contact with the local population.
Persons without a working spleen are especially at risk, as are
persons with a certain deficiency in their blood's immune system.
Primary Protection Measures
The only reasonable precaution travelers at risk may take
to avoid contracting this disease (other than vaccination) is
to stay away from crowded areas frequented by local inhabitants,
to avoid other close physical contact, and to wash their hands
after touching hands or objects that may possibly be contaminated
with nasal secretions.
The vaccine for meningococcal meningitis is an injectable,
inactivated-bacteria vaccine. Vaccination is recommended for some
travelers to countries recognized as having epidemic meningococcal
disease, especially if they will have prolonged or intimate contact
with the local populace. You should consider the vaccine if you
will be traveling to sub-Saharan Africa, especially during the
dry season (December to June), and/or to Burundi, Kenya, Tanzania,
Nepal or New Delhi (India) at any time during the year.
Because invasive meningococcal disease can progress rapidly
into fatalities, early detection and prompt, intensive treatment
with antibiotics are extremely important.
A person with meningococcal meningitis can transmit the disease
as long as symptoms persist (or until 24 hours after effective
treatment was begun), and carriers without symptoms can transmit
the disease for about 6 months.
Antimicrobial therapy must be started immediately. Penicillin
is prescribed and is given intravenously for this disease. Intravenous
mannitol can be used to treat the complications arising from the
increased intracerebral pressure. Sometimes systemic corticosteroids
The death rate ranges from 5% to 15%; with young children
and adults over 50 having the highest death rate.