Meningitis is an infection that causes inflammation of the membranes (meninges) that protect the brain and spinal cord. Depending on the type of infection, meningitis could go away without treatment in a matter of weeks, or become dangerous and even life-threatening.

Several bacteria can cause meningitis:

  • Pneumococcus disease results from the bacteria Streptococcus pneumoniae. It causes pneumonia, ear, and sinus infections. It’s the most common culprit in bacterial meningitis.
  • Neisseria meningitidis and less often Staphylococcus aureus can also cause meningitis.
  • Haemophilus influenzae type b (Hib) was once the most common cause of bacterial meningitis, until the Hib vaccine became standard in children.
  • Meningococcus refers to infections caused by N. meningitidis. It’s the most contagious bacteria behind meningitis, and is known for causing outbreaks in college dorms.
  • Listeria is found in some meats and cheeses, and can be dangerous to pregnant women and the elderly.

There are three main types of meningitis, which are based on the type of infection:

  • viral meningitis
  • fungal meningitis
  • bacterial meningitis

Initial symptoms are the same in all types, and generally consist of:

  • sudden high fever
  • stiff neck
  • headaches

A viral infection is the most common cause of meningitis in the United States. Several viruses can lead to meningitis. Most of these causal viruses are in the enterovirus family.

Less commonly, other viruses like HIV, herpes simplex, and the West Nile virus can lead to meningitis. Most often, when a virus is to blame, the infection is usually fairly mild, and may even go away without treatment.

In most cases, no treatment is necessary for viral meningitis. Certain treatments can be helpful, depending on the virus that caused the infection. Also, some people may require in-patient care if they fall into a higher-risk category. This includes:

  • people with weakened immune systems
  • older adults
  • newborns and infants

A fungal infection is the least common cause of meningitis in most parts of the world. It’s not usually spread from an infected person to other people. Generally, it affects people with weakened immune systems.

People with HIV or cancer are at higher risk of fungal meningitis. The fungi usually responsible are Cryptococcus, which can be inhaled from bird droppings, and Histoplasma, found in bird or bat droppings.

Fungal meningitis is usually treated with antifungal medications. These medications are injected into a vein. If you have fungal meningitis, you can expect to enter the hospital for treatment. The length of your stay depends on the condition of your immune system. In some cases, you will need to continue maintenance treatment for a long period of time.

Bacterial meningitis is caused by bacteria. Usually, the bacteria enter the bloodstream and then travel to the meninges. It’s also possible to introduce bacteria directly in the meninges through sinus infections or ear infections.

Bacterial meningitis is a medical emergency and must be treated quickly. It can be life-threatening if it’s not treated rapidly.

You should be kept in the hospital while being treated with antibiotic medication. With prompt and proper antibiotic treatment, the risk of death as a result of meningitis isn’t likely.

If you have symptoms of meningitis, you should immediately call your doctor. They can run tests to see if you have the disease, and determine the type of infection you may have.

If you suspect you have been in contact with someone who has meningitis, it’s also important to let your doctor know. In cases of bacterial meningitis, prompt treatment is critical to avoid serious and life-threatening complications.