Meningitis is an inflammation of the membranes that line the brain and spinal cord. It is usually caused by infection.
The central nervous system, also called the CNS, consists of the brain and spinal cord. Three layers of fibrous tissue cover the surfaces of the brain and spinal cord. These layers cushion and protect the CNS.
Sometimes organisms, such as bacteria or viruses, can infect these layers. When this happens, the body takes steps to defend itself from infection. White blood cells and other infection-fighting substances pour into the cerebrospinal fluid, or CSF. This is the fluid that circulates within the brain and over its surface. This process results in a set of symptoms known as meningitis.
Meningitis can be caused by a number of different organisms, including:
Following are some of the risk factors for meningitis in children: