The membranes that cover the brain and spinal cord are called the meninges. The meninges are three ultrathin membrane layers that are surrounded by a fluid. Meningitis is a condition when the fluid surrounding the meninges becomes infected. Bacterial or viral infections affect the meninges. They may also be infected due to cancer, medication allergies, chemical reactions or fungal infections. The types of meningitis are based on the cause of meninges infection.

The brain and spinal tissue swell up due to meningitis. Due to the swelling, the oxygen and blood supply to the brain is inhibited. The most common symptoms of meningitis are fever, severe headache, and a stiff neck.

Types of meningitis
Viral and bacterial meningitis are the two main types of meningitis.

Viral meningitis : This is mainly caused by a virus called enterovirus. Other types of viruses like herpes, HIV and West Nile virus may also cause viral meningitis. Among the types of meningitis, viral meningitis is the least severe. The enterovirus is found in the gastrointestinal tract. During the time that our immunity system is lowered, the enterovirus activates and causes flu-like symptoms. The enterovirus spreads through a sneeze, cough, and unclean hands.

Bacterial meningitis : Bacterial meningitis is rare, but severe among the types of meningitis.

Fungal meningitis : This type is rarer than bacterial meningitis. Unlike the other two types of meningitis, fungal meningitis is not contagious. Fungal meningitis occurs when fungi travel to the spinal cord through the bloodstream. Children and elderly are at a higher risk of developing fungal meningitis due to their weak immune system.

Parasitic meningitis : This is the rarest type of meningitis caused by the parasites. These parasites increase the number of white blood cells present in the cerebrospinal fluid. Parasitic meningitis is also referred to as eosinophilic meningitis. This type of parasitic meningitis is extremely rare and spreads from the infected animals consumed by humans.

Non-infectious meningitis : This type of meningitis is not caused by an infection, but by other medical conditions like head injury, spinal injury, brain surgery, cancer, medication reactions or lupus.

Treatment for meningitis
Diagnosis of meningitis is usually done through blood cultures, a spinal tap or imaging techniques. Treatment for meningitis depends on the type of meningitis and the severity. Symptoms of meningitis are more or less similar for all the types. Immediate treatment of meningitis prevents it from developing into a life-threatening condition.

Bacterial meningitis requires immediate medical treatment. Early treatment helps in preventing further damage and death. Intravenous antibiotics are administered for treating bacterial meningitis.

Fungal meningitis is treated by administering high-potency antifungal medication.

Viral meningitis usually resolves on its own, but severe cases may require intravenous anti-viral medication. Recovery usually happens within 7 to 10 days with a good amount of rest and hydration. Other symptoms like fever, joint pain or a headache can be relieved through over-the-counter medication.

In the case of parasitic meningitis, the symptoms are first treated. If the infection does not resolve after symptomatic treatment, medication for the infection is given.

Meningitis can be prevented through vaccinations. Although vaccines are not available for all types of meningitis, most of the types of meningitis can be prevented through vaccination. Meningococcal conjugate vaccine and MenB vaccine are the two types of meningitis vaccine. The meningococcal vaccine protects against four most common types of bacterial meningitis. The effect of this vaccine is for a long duration of time. The MenB vaccine, in contrast, is for a particular strain of bacteria and its effect lasts for a shorter duration. The five groups of people who should get vaccinated against meningitis are as follows:

• College freshmen who share dormitories, hence, prone to meningitis
• Adolescents between the ages of 11 and 12 years
• Those traveling to locations where meningitis is prevalent
• Children aged two years and above whose spleen has been removed, or have a weak immune system.

These vaccines have side effects like redness, soreness, and burning sensation at the site of injection. Some people experience other side effects like fever, chills, joint pain, fatigue, and headache.

Meningitis may be caused by bacterial, viral, fungal, parasitic infections or non-infectious medical conditions. The type and severity of meningitis determine the line of treatment. Early diagnosis and treatment of meningitis help in preventing further damage and death due to infection.