Meningitis typically starts when a bacteria or virus enters the spinal fluid surrounding the brain and spinal cord, usually through the bloodstream.
Here's a more detailed explanation:
-
The Meninges: Meningitis is an infection and inflammation of the meninges. The meninges are the protective membranes that cover the brain and spinal cord.
-
Entry Point: The infection most commonly starts when a bacteria or virus makes its way into the cerebrospinal fluid (CSF). The CSF is the fluid that surrounds and cushions the brain and spinal cord.
-
Common Pathways:
- Bloodstream: Often, the bacteria or virus travels through the bloodstream from another infection site in the body (e.g., respiratory infection).
- Direct Invasion: In some cases, the infection can spread directly from nearby infections, such as a sinus infection or ear infection.
- Injuries: Rarely, meningitis can result from direct invasion due to skull fractures or surgery.
-
Causes: While bacteria and viruses are the most common causes, meningitis can also be caused by fungi, parasites, or even certain medications.
-
Progression: Once in the CSF, the infectious agent multiplies and causes inflammation of the meninges. This inflammation leads to the characteristic symptoms of meningitis, such as headache, stiff neck, fever, and sensitivity to light.
In summary, meningitis typically originates when an infectious agent, usually a bacteria or virus, gains access to the cerebrospinal fluid surrounding the brain and spinal cord, most frequently through the bloodstream.
