What Is Meningitis?
Meningitis is an inflammation of the meninges. The meninges are
the three membranes that cover the brain and spinal cord. Meningitis can occur
when fluid surrounding the meninges becomes infected.
The most common causes of meningitis are viral and bacterial
infections. Other causes may include:
- chemical irritation
- drug allergies
Viral and bacterial meningitis are contagious. They can be
transmitted by coughing, sneezing, or close contact.
Types of Meningitis
Viral and bacterial infections are the most common causes of
meningitis. There are several other forms of meningitis. Examples include
cryptococcal, which is caused by a fungal infection, and carcinomatous, which
is cancer-related. These types are rare.
Viral meningitis is the most common type of meningitis. Viruses
in the Enterovirus category cause 85 percent
of cases. These are more common during the summer and fall, and they include:
Viruses in the Enterovirus category
cause about 10 to
15 million infections per year, but only a small percentage of people who
get infected will develop meningitis.
Other viruses can cause meningitis. These include:
- West Nile
- herpes viruses
which causes Colorado tick fever
Viral meningitis typically goes away without treatment.
Bacterial meningitis is contagious and caused by infection from certain
bacteria. It’s fatal if left untreated. Between 5 to 40 percent
of children and 20
to 50 percent of adults with this condition die. This is true even with
The most common types of bacteria that cause bacterial meningitis
pneumoniae, which is typically found in the respiratory tract, sinuses, and
nasal cavity and can cause what’s called “pneumococcal meningitis”
- Neisseria meningitidis,
which is spread through saliva and other respiratory fluids and causes what’s
called “meningococcal meningitis”
influenza, which can cause not only meningitis but infection of the blood,
inflammation of the windpipe, cellulitis, and infectious arthritis
monocytogenes, which is a foodborne bacteria
What Are the Symptoms of Meningitis?
The symptoms of viral and bacterial meningitis can be similar in
the beginning. However, bacterial meningitis symptoms are usually more severe.
The symptoms also vary depending on your age.
Viral Meningitis Symptoms
Viral meningitis in infants may cause:
- decreased appetite
- a fever
In adults, viral meningitis may cause:
- a fever
- stiff neck
- sensitivity to bright light
- decreased appetite
Bacterial Meningitis Symptoms
Bacterial meningitis symptoms develop suddenly. They may include:
- altered mental status
- a sensitivity to light
- a headache
- a fever
- a stiff neck
Seek immediate medical attention if you experience these
symptoms. Bacterial meningitis can be deadly. There’s no way to know if you
have bacterial or viral meningitis just by judging how you feel. Your doctor
will need to perform tests to determine which type you have.
What Are the Complications from Meningitis?
These complications are typically associated with meningitis:
- hearing loss
- brain damage
- a subdural effusion, or a buildup of fluid between
the brain and the skull
What Are the Risk Factors for Meningitis?
The following are some of the risk factors for meningitis:
People with an immune deficiency are more vulnerable to
infections. This includes the infections that cause meningitis. Certain disorders
and treatments can weaken your immune system. These include:
- autoimmune disorders
- organ or bone marrow transplants
which is caused by a fungus, is the most common form of meningitis in people
with HIV or AIDS.
Meningitis is easily spread when people live in close quarters.
Being in small spaces increase the chance of exposure. Examples of these
- college dormitories
- boarding schools
- day care centers
Pregnant women have an increased risk of listeriosis, which is an
infection caused by the Listeria
bacteria. Infection can spread to the unborn child.
All ages are at risk for meningitis. However, certain age groups
have a higher risk. Children under the age of 5 are at increased risk of viral
meningitis. Infants are at higher risk of bacterial meningitis.
Working with Animals
Farm workers and others who work with animals have an increased
risk of infection with Listeria.
How Is Meningitis Diagnosed?
Diagnosing meningitis starts with a health history and physical
exam. Age, dorm residence, and day care center attendance can be important
clues. During the physical exam, your doctor will look for:
- a fever
- an increased heart rate
- neck stiffness
- reduced consciousness
Your doctor will also order a lumbar puncture. This test is also
called a spinal tap. It allows your doctor to look for increased pressure in the
central nervous system. It can also find inflammation or bacteria in the spinal
fluid. This test can also help determine the best antibiotic for treatment.
Other tests may also be ordered to diagnose meningitis. Common
tests include the following:
cultures identify bacteria in the blood. Bacteria can travel from the
blood to the brain. N. meningitidis
and S. pneumoniae can cause both
sepsis and meningitis.
- A complete
blood count with differential is a general index of health. It checks
the number of red and white blood cells in your blood. White blood cells fight
infection. The count is usually elevated in meningitis.
- Chest X-rays
can reveal the presence of pneumonia, tuberculosis, or fungal infections.
Meningitis can occur after pneumonia.
- A CT scan
of the head may show problems like a brain abscess or sinusitis.
Bacteria can spread from the sinuses to the meninges.
How Is Meningitis Treated?
Your treatment is determined by the cause of your meningitis.
Bacterial meningitis requires
immediate hospitalization. Early diagnosis and treatment will prevent brain
damage and death. Bacterial meningitis is treated with intravenous antibiotics.
There’s no specific antibiotic for bacterial meningitis. It depends on the
Fungal meningitis is
treated with antifungal agents.
Viral meningitis isn’t
treated. It usually resolves on its own. Symptoms should go away within two
weeks. There are no serious long-term problems associated with viral
How Is Meningitis Prevented?
Maintaining a healthy lifestyle, especially if you’re at
increased risk, is important. This includes things like:
- getting adequate amounts of rest
- not smoking
- avoiding contact with sick people
If you’ve been in close contact with one or more people who have
a bacterial meningococcal infection, your doctor can give you preventive
antibiotics. This will decrease your changes of developing the disease.
Vaccinations can also protect against certain types of
meningitis. Vaccines that can prevent meningitis include the following:
influenzae type B (Hib) vaccine
- pneumococcal conjugate vaccine
- meningococcal vaccine
Who Should Be Vaccinated Against Meningococcal Meningitis?
These five groups are considered at risk and should get a
- college freshmen who live in dorms and haven’t
- adolescents who are 11 to 12 years old
- new high school students who haven’t been
- people traveling to countries where
meningococcal disease is common
- children who are ages 2 or older and who don’t
have a spleen or have a compromised immune system