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.
There are several types of bacteria that can cause meningitis. Leading causes in the United States include

• Streptococcus pneumoniae
• Group B Streptococcus
• Neisseria meningitidis
• Haemophilus influenzae
• Listeria monocytogenes

On average, bacterial meningitis caused about 4,100 cases and 500 deaths in the United States each year between 2003 and 2007
These bacteria can also be associated with another serious illness, Sepsis is the body’s overwhelming and life-threatening response to infection that can cause tissue damage, organ failure, and death.

Causes

Common causes of bacterial meningitis vary by age group:

• Newborns: Group B Streptococcus, Streptococcus pneumoniae, Listeria monocytogenes, Escherichia coli
• Babies and children: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type b (Hib), group B Streptococcus
• Teens and young adults: Neisseria meningitidis, Streptococcus pneumoniae
• Older adults: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae type b (Hib), group B Streptococcus, Listeria monocytogenes

Risk Factors

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.
• Community setting
  • Infectious diseases tend to spread where large groups of people gather together. 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