Many people have heard of meningitis but don’t know exactly what it is. Meningitis refers to any inflammation of the tissues (meninges) that surround the brain and spinal cord. The meninges cushion these delicate structures and provide an added barrier against infectious agents like viruses, bacteria and fungi—but some microorganisms get through. Some forms of meningitis are relatively mild and clear up with little medical intervention, but other types can turn lethal quickly. Accurately diagnosing the specific type of meningitis is key to receiving potentially life-saving treatment as rapidly as possible. Bacterial Meningitis: A Dangerous Infection Several germs can cause bacterial meningitis. The main culprits are: Group B Streptococcus, responsible for many types of strep infections like strep throat Haemophilus influenzae, also known as ‘Hib’ Listeria monocytogenes, often spread through contaminated food Neisseria meningitidis, which causes the meningococcal form of meningitis Streptococcus pneumoniae, which also causes a variety of pneumococcal diseases like sinus infection Bacterial meningitis requires fast, aggressive medical intervention. To definitively diagnose bacterial meningitis, doctors look at a sample of cerebrospinal fluid (CSF) under a microscope. With a bacterial meningitis diagnosis, treatment turns toward infusions of powerful antibiotics to destroy the bacterium causing the illness, corticosteroids to limit swelling of the meninges, and sometimes advanced care measures like breathing support. Viral Meningitis: The Most Common Form Fortunately, bacterial meningitis has become rare in the United States, thanks to the widespread use of vaccines. Today, it’s much more common for people to experience viral meningitis, which rarely is life threatening. Viral meningitis occurs when a virus enters the body and, in addition to following its usual course, attacks the meninges. Many viruses can cause meningitis, including West Nile, herpes and chickenpox. Viral meningitis is not transmitted from person to person. Sometimes a virus will infect only the meninges of the spinal cord, which is called spinal meningitis. Although viral meningitis often creates only mild symptoms like headache or a stiff neck, any type of suspected meningitis requires a medical diagnosis. Because the symptoms of all types of meningitis are identical at first, only an examination of CSF under a microscope can determine if the meningitis is caused by a virus, bacterium or fungus. Viral meningitis will oftentimes clear up on its own, but some cases may respond to antiviral medicine. Hospitalization to provide supportive medical care may be necessary for serious cases in at-risk populations, including infants and people with weak immune systems. Fungal Meningitis: Very Rare Fungal meningitis most often occurs from inhaling a common environmental fungus called Cryptococcus. People breathe Cryptococcus every day and almost never get sick from it, but from time to time it does infect the meninges. People with a compromised immune system face the highest risk of developing fungal meningitis. Fungal meningitis cannot be spread from one person to another. On rare occasion, a fungus can be transmitted through contaminated medical supplies, such as an incident in 2012 when a number of patients developed fungal meningitis after being injected with contaminated corticosteroid solution. This type of situation is extremely rare, but any action that introduces a fungus into the bloodstream can theoretically cause fungal meningitis. The symptoms of fungal meningitis are the same as viral and bacterial meningitis and include a sudden, high fever, stiff or sore neck (difficulty touching the chin to the chest), and sometimes nausea, body aches, and other flu-like symptoms. Any suspected case of meningitis requires immediate medical attention, since a definitive diagnosis requires examining a sample of CSF to detect bacteria, viruses or fungi. Fungal meningitis can turn serious if left untreated. Treatment usually includes high dosage intravenous antifungal medicine to destroy the fungus causing the meningitis. Fungal meningitis treatment might take months or even years, depending on the overall health status of the individual. Other Infectious Types of Meningitis Primary amebic meningitis, caused by the ameba Naegleria fowleri, is another, oftentimes fatal type of meningitis. Certain parasites can cause meningitis too. Both amebic and parasitic meningitis are rare. Prevention of Infectious Meningitis For viral meningitis, some regular vaccine recommendations, such as the measles, mumps, influenza and chickenpox, can help protect you. That’s because the viruses that cause these diseases also have the potential to cause meningitis. Staying up to date on recommended vaccinations will protect you from these causes of viral meningitis. However, there are many other viruses that can cause meningitis, so washing your hands and staying away from sick people will help you avoid viral infections. There is no vaccine for fungal meningitis. If you are at increased risk for dangerous infections, you may need to take extra precautions to protect yourself from breathing in the fungus. To help prevent bacterial meningitis, all children should receive the meningococcal vaccine at age 11 or 12, with a booster dose at age 16. Some babies and young children also should receive the vaccine, as well as certain adults. Adults in good health who do not have weakened immune systems usually do not need the meningococcal vaccine. Discuss the meningococcal vaccination with your doctor, and be sure to seek prompt medical attention for any signs and symptoms of meningitis. There also are vaccines against pneumococcal disease and Haemophilus influenzae Type B (Hib), two other causes of bacterial meningitis. They are part of a child’s recommended vaccine schedule. Adults at increased risk for Hib disease may receive the Hib vaccine. Healthcare professionals recommend adults older than 65 years get the pneumococcal vaccine. Non-infectious Meningitis Meningitis can also result from non-infectious causes, so they cannot spread between people. Conditions that can cause meningitis include head trauma, spinal injury, lupus, and cancer. Treatment of the underlying condition may resolve the inflammation and help prevent complications.