Table of ContentsView AllTable of ContentsSymptomsTypesRisk FactorsPrevention
Table of ContentsView All
View All
Table of Contents
Symptoms
Types
Risk Factors
Prevention
Meningitisis inflammation or infection of the meninges andcerebrospinal fluid (CSF). Meninges are three layers of protective tissue surrounding the brain andspinal cord. CSF is a special fluid between the layers of the meninges that nourishes the brain.
According to the World Health Organization (WHO), the worldwide incidence of meningitis is approximately 82 million cases per year.The Centers for Disease Control and Prevention (CDC) estimates that over 1.2 million cases of bacterial meningitis (a dangerous type of meningitis) occur worldwide each year.
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Meningitis Symptoms
Meningitis usually causes nonspecific symptoms, but sometimes it can cause focal neurological symptoms (those that affect a specific function or part of the body).
Common symptoms of meningitis include:
Apetechial rashthat looks like clusters of tiny purplish dots on the skin can occur with bacterial meningitis, especially meningococcal meningitis.
Signs of meningitis in babies include crying, being fussy, losing appetite, vomiting, sleeping excessively, decreased alertness, and reduced physical activity. The soft spot at the front of the skull (anterior fontanelle) may bulge.
Less commonly, meningitis can cause symptoms suggestive of brain involvement, including:
Generally, viral meningitis and noninfectious meningitis cause mild to moderate generalized symptoms but can progress to severe symptoms and complications.
Bacterial meningitis may cause rapidly worsening generalized or focal symptoms, with a high risk of complications. Fungal, parasitic, and amebic meningitis are not common and may cause focal symptoms and/or seizures.
Complications
If meningitis is not adequately treated, it can lead to severe acute illness that requires intensive treatment. And sometimes meningitis leads to long-term problems, such as permanent hearing loss or cognitive deficits.
Meningitis Facts and Statistics: What You Need to Know
Types of Meningitis
There are several types of infectious and noninfectious meningitis. They have different risk factors, anticipated outcomes, treatments, and complications.
Meningitis can be diagnosed based on symptoms and physical examination, andbrain imaging studiescan show signs of inflammation of the meninges. The specific type of meningitis and infectious organism can be identified with alumbar puncture (LP), which is an invasive test.
How to Spot a Meningitis Rash (And What to Do Next)
Viral Meningitis
You can develop viral meningitis as a complication of an infection with any of these viruses, although most people who contract them do not. Anyone can develop viral meningitis, but it is more common among children. Sometimes it is diagnosed clinically, without an LP.
Bacterial Meningitis
Bacterial meningitis is the second most common type of infectious meningitis, and it can be dangerous. The most common causes areStreptococcus pneumonia,Neisseria meningitidis,Haemophilus influenzae,Listeria monocytogenes, and group BStreptococcus.These organisms are prevalent in the environment and are contagious.
The symptoms can progress rapidly, and treatment should be targeted to the infectious organism. Generally, the bacteria is identified with an LP. Anyone can develop bacterial meningitis, but it is more common among people who have an impaired immune system or who have had brain surgery or head trauma.
Fungal Meningitis
The organisms that can cause fungal meningitis are prevalent in the community. It is common to come into contact with them, but they normally do not cause infections in healthy people.
Fungal Infections of the Nervous System
Parasitic Meningitis
Parasites can invade the body, with exposure due to contamination from food that isn’t fully cooked or from the environment. According to the CDC, the most common parasites that cause meningitis areAngiostrongylus cantonensis, Baylisascaris procyonis,andGnathostoma spinigerum.
Parasitic infection can cause brain inflammation, and it may also appear like a mass or a growth in the brain. Parasites can reproduce after invading the body, or they may die and remain in the body, continuing to produce a mass effect in the brain. It is treated with antimicrobials, and the organism may be removed surgically.
Parasitic Infections of the Nervous System
Amebic Meningitis
Amebic meningitis is very rare. Amoeba is a type of single-celled organism that usually lives in freshwater, lakes, rivers, soil, or contaminated sewer water. Organisms that can cause amebic meningitis includeNaegleria fowleriandAcanthamoebaspecies.
Because the condition is rare, it may not be easily recognized, and brain imaging studies may identify a pattern of inflammation.
Amebic meningitis is often described as meningoencephalitis because the infection and inflammation affect the brain in addition to the meninges. Symptoms may progress, and complications can occur if the condition worsens.
Treatment may include a combination of antimicrobials that are usually used to treat fungal infections, as well as surgical treatment for fluid pressure in and around the brain.
Amoebas That Can Cause Fatal Brain Disease
Noninfectious Meningitis
Inflammation of the meninges and CSF can occur without an infection. Sometimes referred to as aseptic meningitis, this can occur due to autoimmune diseases likelupus,sarcoidosis, or rheumatoid arthritis.
Not everyone who has these autoimmune conditions will develop associated meningitis. When it does occur, meningitis due to autoimmune disease will typically be infrequent and may cause fatigue, trouble concentrating, or confusion.
Noninfectious meningitis can also occur as a result of medications or radiation to the brain, which is used to treat cancer.
Cancer is a more serious cause of noninfectious meningitis. It can lead toleptomeningeal carcinomatosis, which is the spread of cancer cells throughout the meninges surrounding the brain and spinal cord. This complication of cancer may be treated with intrathecal chemotherapy, which is injected into the CSF.
Meningitis can affect anyone, but certain risk factors may make it more likely. Noninfectious meningitis is more common among people who have underlying associated conditions, such as sarcoidosis.
Having a weak immune system, such as due to HIV infection or immunosuppressive therapy, is a major risk factor for infectious meningitis.
Immunosuppressive therapies, such as steroids and more targeted drugs, are often prescribed to prevent organ rejection in people who have had an organ transplant, or they may be prescribed to manage chronic inflammatory or autoimmune disease. Chemotherapeutic medications used to treat cancer also cause immunosuppression.
Complications of meningitis are more likely if the condition is not treated. Additionally, having an impaired immune system can predispose someone to worsening meningitis, with an increased risk of long-term effects.
There are several ways to prevent meningitis, and the most well-established preventive strategy is vaccination. The condition is more common in areas of the world where vaccination rates are low.
Vaccines that can prevent meningitis include ones that protect against:
These vaccines are routinely recommended on astandard vaccination schedulein the U.S. Of these, the vaccines forN. meningitidisspecifically aim to prevent meningitis:
Even if you are vaccinated against organisms that cause meningitis, it is possible to develop the condition. Avoiding infection is important for your overall health and can reduce your chances of meningitis.
Strategies for preventing meningitis include:
And, if you develop symptoms of meningitis, seek medical attention right away. Prompttreatmentcan help you avoid complications.
Prevention of Meningitis
A Word From Verywell
Being diagnosed with meningitis can be scary. Most of the time, meningitis resolves with supportive medical treatment, such as fever control, pain control, hydration, and anti-inflammatory medication.
Some types of meningitis require anti-microbial treatment and more extensive interventions, includingventricular shunt placement. With timely treatment, you can experience a good recovery after meningitis.
10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
World Health Organization.Meningitis.
Centers for Disease Control and Prevention.About bacterial meningitis.
KidsHealth from Nemours.Meningitis (for parents).
Centers for Disease Control and Prevention.About viral meningitis.
Centers for Disease Control and Prevention.About fungal meningitis.
Centers for Disease Control and Prevention.About parasitic meningitis.
Pana A, Vijayan V, Anilkumar AC.Amebic meningoencephalitis. In:StatPearls. StatPearls Publishing; 2024.
National Institute of Neurological Disorders and Stroke.Meningitis.
Centers for Disease Control and Prevention.Meningococcal vaccination.
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