Meningitis is a serious condition caused by inflammation of the meninges, the protective membranes surrounding the brain and spinal cord. The infection that causes meningitis can be viral, bacterial or fungal, and the severity of each varies, but treatment is required for all cases.
Bacterial or viral infections are the most likely causes of meningitis, and they usually begin elsewhere in the body, often in the ears, sinuses, or upper respiratory tract. Bacterial meningitis is extremely serious and requires immediate treatment, as it can cause death or permanent brain damage within hours. Many times, a bacterial infection such streptococcus pneumoniae (which normally causes pneumonia or ear infections) enters the bloodstream from another part of the body, thereby traveling to the brain and infecting it. This kind of meningitis is highly contagious and is spread through the exchange of saliva or mucus; close or crowded communities are at most risk – colleges and military bases are common outbreak sites.
Viral meningitis is more common and less serious than its bacterial counterpart, although the need for diagnosis can’t be discounted. Several viruses, including the ones that cause herpes, measles, mumps, and diarrhea, can cause meningitis when they get into the bloodstream; the viral form carries less risk of permanent brain damage or hearing loss, and in some cases it may clear up on its own. People with an already weakened immune system are most at risk. There is no way of determining whether meningitis is bacterial or viral without a spinal fluid test, so a visit to the doctor or a hospital is important.
Although it is possible, a fungal infection is the most unlikely cause of meningitis, occurring when someone inhales fungal spores. It occurs very rarely in healthy people, but those with compromised immune systems, such as AIDS or cancer patients, can be severely affected, especially if they don’t receive anti-fungal treatment in time. Unlike bacterial meningitis, fungal meningitis is not contagious.
If you have the symptoms of meningitis – sensitivity to light, stiff and painful neck, confusion, nausea and vomiting, fever – seek medical treatment immediately. Those most at risk are children under 5, teenagers and young adults, and adults over 55.