Bacterial meningitis is usually more severe than the viral meningitis. Bacterial meningitis can
have serious after-effects, such as brain damage, hearing loss, limb amputation, or learning
disabilities. Neisseria meningitidis is the leading cause of bacterial meningitis in children and
young adults in the United States. Other causes include Streptococcus pneumoniae, Group B
streptococcus disease and Haemophilus influenzae Serotype b disease.
There are two vaccines against Neisseria meningitidis available in the United States:
meningococcal polysaccharide vaccine (MPSV4 or Menomune®), and meningococcal
conjugate vaccine (MCV4 or Menactra®).
Viral ("aseptic") meningitis is serious but rarely fatal in persons with normal immune systems.
Usually, the symptoms last from 7 to 10 days and the patient recovers completely.
Many different viruses can cause meningitis. About 90% of cases of viral meningitis are
caused by members of a group of viruses known as enteroviruses, such as coxsackieviruses
and echoviruses. These viruses are more common during summer and fall months.
Herpesviruses and the mumps virus can also cause viral meningitis.
Viral meningitis is usually diagnosed by laboratory tests of spinal fluid.
No specific treatment for viral meningitis exists at this time. Most patients completely recover
on their own. Doctors often will recommend bed rest, plenty of fluids, and medicine to relieve
fever and headache
Enteroviruses, the most common cause of viral meningitis, are most often spread through
direct contact with respiratory secretions (e.g., saliva, sputum, or nasal mucus) of an infected
person. This usually happens by shaking hands with an infected person or touching
something they have handled, and then rubbing your own nose or mouth. The virus can also
be found in the stool of persons who are infected.
The viruses that cause viral meningitis are contagious. Enteroviruses, for example, are very
common during the summer and early fall, and many people are exposed to them. However,
most infected persons either have no symptoms or develop only a cold or rash with low-grade
Adhering to good personal hygiene can help to reduce your chances of becoming infected.
The most effective method of prevention is to wash your hands thoroughly and often. Also,
cleaning contaminated surfaces and soiled articles first with soap and water, and then
disinfecting them with a dilute solution of chlorine-containing bleach.
Lymphocytic choriomeningitis, or LCM, is a rodent-borne viral infectious disease that
presents as aseptic meningitis (inflammation of the membrane, or meninges, that surrounds
the brain and spinal cord), encephalitis (inflammation of the brain), or meningoencephalitis
(inflammation of both the brain and meninges).
The primary host is the common house mouse, Mus musculus. The virus is found in the
saliva, urine, and feces of infected mice. Infected mice carry LCMV and shed it for the
duration of their lives without showing any sign of illness. Other types of rodents, such as
hamsters, are not the natural reservoirs but can become infected with LCMV from wild mice
at the breeder, in the pet store or home environment. Humans are more likely to contract
LCMV from house mice, but infections from pet rodents have also been reported.
Individuals become infected with LCMV after exposure to fresh urine, droppings, saliva, or
nesting materials. Transmission can also occur when these materials are directly introduced
into broken skin, the nose, the eyes, or the mouth, or presumably, via the bite of an infected
Some people infected with LCMV do not become ill. For infected persons who do become ill,
onset of symptoms usually occurs 8-13 days after being exposed to the virus. A characteristic
biphasic febrile illness then follows. The initial phase, which may last as long as a week,
typically begins with any or all of the following symptoms: fever, malaise, lack of appetite,
muscle aches, headache, nausea, and vomiting. Other symptoms that appear less frequently
include sore throat, cough, joint pain, chest pain, testicular pain, and parotid (salivary gland)
pain. Following a few days of recovery, the second phase of the disease occurs, consisting of
symptoms of meningitis (for example, fever, headache, and a stiff neck) or characteristics of
encephalitis (for example, drowsiness, confusion, sensory disturbances, and/or motor
abnormalities, such as paralysis). LCMV has also been known to cause acute hydrocephalus
(increased fluid on the brain), which often requires surgical shunting to relieve increased
During the first phase of the disease, the most common laboratory abnormalities are a low
white blood cell count (leukopenia) and a low platelet count (thrombocytopenia). Liver
enzymes in the serum may also be mildly elevated. After the onset of neurological disease
during the second phase, an increase in protein levels, an increase in the number of white
blood cells or a decrease in the glucose levels in the cerebrospinal fluid (CSF) is usually
LCM is usually not fatal. In general, mortality is less than 1%. Aseptic meningitis, encephalitis,
or meningoencephalitis requires hospitalization and supportive treatment based on severity.
Anti-inflammatory drugs, such as corticosteroids, may be considered under specific
circumstances. Although studies have shown that ribavirin, a drug used to treat several other
viral diseases, is effective against LCMV in vitro.
LCMV infection can be prevented by avoiding contact with house mice and taking
precautions when handling pet rodents (i.e. mice, hamsters, or guinea pigs).
|Meningitis is an infection of the fluid
of a person's spinal cord and the fluid
that surrounds the brain. People
sometimes refer to it as spinal
meningitis. Meningitis is usually
caused by a viral or bacterial
infection. Viral meningitis is generally
less severe and resolves without
specific treatment, while bacterial
meningitis can be quite severe and
may result in brain damage, hearing
loss, or learning disability.
Discuss with your doctor before taking any alternative medicine. This article is for