Bacterial Meningitis: Causes

What causes bacterial meningitis?

The most common causes of bacterial meningitis include Haemophilus influenzae type b (also known as Hib), Neisseria meningitidis, and Streptococcus pneumoniae, although Haemophilus influenzae type b is not as common as it once was due to vaccination practices. Other bacteria that can cause bacterial meningitis include Escherichia coli, group B streptococci, Listeria monocytogenes, and Mycobacterium tuberculosis.

Bacterial meningitis is contagious and spreads from person to person through tiny droplets that are sent into the air during talking, laughing, coughing and sneezing. It can also spread by kissing, sharing eating utensils, and hand-to-hand contact. Bacterial meningitis can also be a complication of blood infection or infections in nearby sites, such as the sinuses or ears. Bacterial meningitis tends to occur in settings where people are in close contact with each other, such as daycare and school.

What are the risk factors for bacterial meningitis?

A number of factors increase the risk of developing bacterial meningitis. Not all people with risk factors will get bacterial meningitis. Risk factors for bacterial meningitis include:

• Attendance or work in a daycare or school setting
• Close contact with an infected person
• Exposure to insects or animals that might carry the disease
• Infrequent hand washing
• Lack of vaccination against the disease
• Otitis media (middle ear infection)
• Sinusitis (inflammation or infection of the sinuses)
• Weakened immune system

Reducing your risk of bacterial meningitis

You may be able to lower your risk of bacterial meningitis by:

• Getting treated if you have a bacterial sinus or ear infection
• Getting vaccinated against Haemophilus influenzae type b, Neisseria meningitidis, and Streptococcus pneumoniae
• Staying indoors when biting insects such as mosquitoes are out in large number
• Washing your hands frequently, especially after contact with someone who has meningitis