The brain and spinal cord are covered by layers of tissue. These layers are called the meninges. Certain bacteria can cause an infection in these layers. This is called bacterial meningitis.

It is a serious infection that causes inflammation of the brain and spinal tissue. Bacterial meningitis is a medical emergency and requires immediate treatment. Depending on the severity of the infection, it can result in death within hours.

Bacterial Meningitis
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Bacterial meningitis is caused by many different bacteria and varies by age group. The most common are pneumococcal meningitis, meningococcal meningitis, and Hemophilus influenza B meningitis. The brain and spinal cord are protected from the bloodstream by the blood-brain barrier. Under certain circumstances bacteria in the bloodstream can travel through the blood-brain barrier into the cerebrospinal fluid that surrounds the brain and spinal cord causing meningitis. Severity of the infection depends on the bacteria causing it.

Transmission of the bacteria usually occurs by direct contact with oral or respiratory secretions, such as inhaling droplets from someone who sneezes or coughs, or by kissing. The spread of the bacteria depends on the time of the year, crowding, and the presence other respiratory infections.