Bacterial Meningitis Causes & Risks

Causes

The bacteria first cause an upper respiratory tract infection . Then it travels through the blood stream to the brain.

Worldwide, three types of bacteria cause the majority of cases of acute bacterial meningitis:

• Streptococcus pneumoniae (the bacteria that causes pneumonia )
• Neisseria meningitidis
• Haemophilus influenzae b (Hib)
  • In the US, widespread immunization has almost eliminated meningitis due to Hib

Other forms of bacterial meningitis include:

• Listeria monocytogenes meningitis
• Escherichia coli meningitis
• Mycobacterium tuberculosis meningitis

Newborn babies and the elderly are more prone to get sick.

Some forms are spread by direct contact with fluid from the mouth or throat of an infected person. This can happen during a kiss or by sharing eating utensils. In general, meningitis is not spread by casual contact.

Risk Factors

If you have any of these risk factors for meningitis, tell your doctor:

• Age: infancy and early childhood; over 60 years of age
• People in close and prolonged contact with patients with meningitis due to Hib or Neisseria meningitidis
• A weakened immune system due to HIV infection or other conditions
• Alcoholism
• Smoking (for meningitis due to Neisseria meningitidis )
• Living in proximity to others, such as dormitories and military barracks (for meningitis due to Neisseria meningitidis )