Meningitis is a disease that can be
passed from person to person (contagious). It is caused most often by viruses
or bacteria that infect the tissues (meninges ) and sometimes the fluid
(cerebral spinal fluid, or CSF) that surround the brain and spinal cord.
Enteroviruses are the most common cause of viral
meningitis. They can live in your
intestines without causing illness. But they can cause
meningitis when they are passed from one person to another through food, water,
or contaminated objects. Meningitis caused by enteroviruses occurs most often
in babies and young children.
In rare cases, other viruses, such
human immunodeficiency (HIV) or
mumps, may cause meningitis.
In the United States, bacterial meningitis mainly affects
adults.1 Immunizations continue to help prevent
childhood bacterial meningitis. Most people who get bacterial meningitis get it
from one of two types of bacteria:
Streptococcus pneumoniae or
These bacteria often live in the body, most
often in the nose and throat, without causing illness. But the bacteria can
cause meningitis if they spread from infected tissue or get into the bloodstream and travel to the
cerebrospinal fluid or the tissues (meninges) that
surround the brain and spinal cord. These bacteria also can be passed from one
person to another, usually through infected saliva or mucus.
other bacteria that sometimes cause meningitis are
group B streptococci and
Meningitis caused by group B streptococci bacteria occurs most often in
newborns, who can become infected during or after birth. Meningitis caused by
Listeria monocytogenes bacteria occurs most often in
newborns and in older adults.
The Centers for Disease Control and
Prevention (CDC) recommends screening for group B streptococci in all pregnant
women at 35 to 37 weeks. Women who have the bacteria are given antibiotics
during labor in order to prevent infection in their newborns, and this practice
has worked well.3
In rare cases, other
bacteria cause meningitis, usually in people with long-term medical
Meningitis also can be caused by
other organisms and conditions. It can be a
complication of an illness, an injury (particularly to the skull or face), or
How meningitis is spread
Organisms that cause
meningitis can be passed from one person to another or passed from rodents and
insects to people. But exposure to an organism that causes meningitis does not
mean you will get the infection.
Organisms can be passed from one
person to another:
- During birth. A mother can pass organisms
that cause meningitis to her baby even if the mother does not have symptoms.
Delivering a baby by cesarean section rather than through the birth canal does
not always protect the baby from getting the infection. Both bacteria and
viruses can be transmitted this way.
- Through stool. Stool could
have enteroviruses or certain types of bacteria in it.
Washing hands on a regular basis can help prevent you
and your children from getting infected this way. More children than adults get
meningitis this way.
- Through coughing and sneezing. Infected people
can pass certain bacteria that are normally found in saliva or mucus in their
noses and throats.
- Through kissing, sexual contact, or contact
with infected blood. The human immunodeficiency virus (HIV) also can cause
meningitis and can be passed from an infected person to another person through
blood or sexual contact but not through kissing.
In rare cases, some organisms that cause meningitis
can be passed to people from rodents and insects. The most common of these are
arboviruses (including the St. Louis encephalitis and West Nile viruses), which
are transmitted through dust and food contaminated by the urine of infected
mice, hamsters, and rats.