Bacterial meningitis is very serious and can be deadly. Death can occur in as little as a few hours. Most people recover from meningitis. However, permanent disabilities (such as brain damage, hearing loss, and learning disabilities) can result from the infection.
Several types of bacteria can cause meningitis. Leading causes in the United States include
- Streptococcus pneumoniae
- Group B Streptococcus
- Neisseria meningitidis
- Haemophilus influenzae
- Listeria monocytogenes
These bacteria can also be associated with another serious illness, sepsis. Sepsis is the body’s extreme response to infection. Without timely treatment, sepsis can quickly lead to tissue damage, organ failure, and death.
Common causes of bacterial meningitis vary by age group:
- Newborns: Group B Streptococcus, S. pneumoniae, L. monocytogenes, E. coli
- Babies and children: S. pneumoniae, N. meningitidis, H. influenzae type b (Hib), group B Streptococcus
- Teens and young adults: N. meningitidis, S. pneumoniae
- Older adults: S. pneumoniae, N. meningitidis, Hib, group B Streptococcus, L. monocytogenes
Certain people are at increased risk for bacterial meningitis. Some risk factors include:
- Age: Babies are at increased risk for bacterial meningitis compared to people in other age groups. However, people of any age can develop bacterial meningitis. See section above for which bacteria more commonly affect which age groups.
- Group setting: Infectious diseases tend to spread where large groups of people gather. College campuses have reported outbreaks of meningococcal disease, caused by N. meningitidis.
- Certain medical conditions: There are certain medical conditions, medications, and surgical procedures that put people at increased risk for meningitis.
- Working with meningitis-causing pathogens: Microbiologists routinely exposed to meningitis-causing bacteria are at increased risk for meningitis.
- Travel: Travelers may be at increased risk for meningococcal disease, caused by N. meningitidis,if they travel to certain places, such as:
- The meningitis belt in sub-Saharan Africa, particularly during the dry season
- Mecca during the annual Hajj and Umrah pilgrimage
How It Spreads
Generally, the germs that cause bacterial meningitis spread from one person to another. Certain germs, such as L. monocytogenes, can spread through food.
How people spread the germs often depends on the type of bacteria. It is also important to know that people can have these bacteria in or on their bodies without being sick. These people are “carriers.” Most carriers never become sick, but can still spread the bacteria to others.
Here are some of the most common examples of how people spread each type of bacteria to each other:
- Group B Streptococcus and E. coli: Mothers can pass these bacteria to their babies during birth.
- Hib and S. pneumoniae: People spread these bacteria by coughing or sneezing while in close contact with others, who breathe in the bacteria.
- N. meningitidis: People spread these bacteria by sharing respiratory or throat secretions (saliva or spit). This typically occurs during close (coughing or kissing) or lengthy (living together) contact.
- E. coli: People can get these bacteria by eating food prepared by people who did not wash their hands well after using the toilet.
People usually get sick from E. coli and L. monocytogenes by eating contaminated food.
How to avoid meningitis
You can reduce your risk of getting or spreading viruses and bacteria by taking a few precautions:
- Wash your hands frequently with warm water and soap. Wash for a full 20 seconds, taking care to clean under fingernails. Rinse and dry thoroughly.
- Wash your hands before eating, after using the toilet, after changing a diaper, or after tending to someone who is ill.
- Don’t share eating utensils, straws, or plates.
- Cover your nose and mouth when you cough or sneeze.
- Stay up to date with immunizations and booster shots for meningitis.
- Ask your doctor about immunizations before traveling to countries with higher rates of meningitis.