Meningitis is an inflammation of the meninges, protective membranes that surround the brain and spinal cord. Anyone can get meningitis, but it is more common in children and those with weakened immune systems. It is a serious disease that can lead to seizures and death; however, treatment is available.

The cause of meningitis determines a person’s treatment. While bacterial or viral infections often cause the swelling of these membranes, other causes may include:

  • fungal infections
  • injuries
  • cancer
  • certain medications
  • other infections

This article discusses the different types of meningitis and their symptoms. It also examines the causes of meningitis and the potential treatment and prevention options.

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Meningitis occurs when the meninges are inflamed or swollen. The meninges generally swell when there is an infection in the fluid surrounding them.

In 2015, 8.7 million people worldwide had meningitis, and about 379,000 died as a result.

There are several types of meningitis, including:

Bacterial

Bacterial infections cause a severe type of bacterial meningitis.

According to the Centers for Disease Control and Prevention (CDC), bacterial meningitis can cause death in just a few hours. It can also cause permanent side effects, such as brain damage or hearing loss.

However, most people recover from bacterial meningitis.

Viral

Viral meningitis is the most common form of meningitis and is generally not as severe as bacterial. Most people with viral meningitis recover without treatment.

Fungal

Fungal meningitis develops when a fungal infection travels to the brain or spinal cord from elsewhere in the body.

Parasitic

Parasitic meningitis happens when a parasite reaches a person’s brain. People can encounter parasites that cause meningitis in uncooked food items and through exposure to raccoon feces.

This type of meningitis is less common than bacterial and viral meningitis.

Amebic

Primary amebic meningoencephalitis (PAM) is a severe and rare form of meningitis that is usually fatal. It results from a water-borne single-celled organism called Naegleria fowleri entering the body through the nose.

The Centers for Disease Control and Prevention (CDC) state that only 148 people reported infections in the United States from 1962–2019.

Noninfectious

Noninfectious meningitis occurs when the meninges swell due to reasons other than a contagious pathogen.

Meningitis symptoms vary depending on the type.

Bacterial

Symptoms of bacterial meningitis generally start 3–7 days after a person has exposure and include:

Viral

Symptoms of viral meningitis are similar to the symptoms of bacterial meningitis but overall can be less severe.

While most people recover from viral meningitis without treatment, a person with meningitis symptoms still needs to see a doctor to rule out other types of meningitis that may require treatment.

Fungal

Symptoms of fungal meningitis are similar to the symptoms of bacterial meningitis and typically start soon after a fungal lung infection.

Unlike bacterial meningitis, the symptoms may not appear for several weeks or even months after exposure to the fungus.

Parasitic

Symptoms of parasitic meningitis generally are similar to symptoms of bacterial meningitis.

Aside from the symptoms of bacterial meningitis, a person may also notice signs of an eye infection, such as:

Parasitic meningitis can also lead to severe complications.

Amebic

Symptoms of PAM start 1–9 days after the initial exposure and are similar to symptoms of bacterial meningitis. Symptoms generally progress quickly and may worsen to include:

Noninfectious

Symptoms of noninfectious meningitis are similar to the symptoms of bacterial meningitis.

Infants, especially newborns, are more susceptible to meningitis due to their immature immune systems.

Parents, caregivers, and doctors may have difficulty recognizing the symptoms of meningitis in infants because the symptoms can be vague.

In infants, a parent or caregiver may notice:

In infants, meningitis is serious and has a high rate of poor outcomes. Doctors will treat infants with meningitis in the hospital with antibiotics or antiviral medications and other interventions.

Learn more about meningitis in children here.

Some people with meningitis may also develop a rash. The rashes differ according to the type of meningitis a person has.

For example, the most common rash occurs due to meningococcal septicemia, or meningococcemia. This is when Neisseria meningitidis bacteria enter the bloodstream and multiply. This damages blood vessels and results in bleeding into the skin and organs, causing a rash.

This rash can be a clear sign of meningococcal meningitis and septicemia. However, meningococcal rashes can be extremely diverse and present differently according to a person’s skin type and color.

Typically, they may appear as a rash that looks like red or purple pin-pricks on the skin or a reddish-purple rash that resembles bruising.

Other types of rash may also develop from meningitis that results from syphilis, herpes simplex virus, or other tick-borne infections.

Learn more about non-blanching meningitis rashes here.

There are a variety of causes of meningitis, including:

  • Bacteria: Group B Streptococcus, Streptococcus pneumoniae,Listeria monocytogenes, and Neisseria meningitides are common bacteria that cause meningitis.
  • Viruses: Non-polio enteroviruses commonly cause viral meningitis. Other viruses that may cause meningitis include mumps, influenza, and herpes viruses.
  • Fungus: Different types of fungi found in the environment cause viral meningitis. Many of the fungi, including Cryptococcus and Histoplasma, are in the soil.
  • Parasites: A person may contract parasitic meningitis from eating food contaminated with a parasite. Foods containing parasites that could cause meningitis include raw or undercooked snails, produce grown in areas where raccoons live, freshwater fish, and poultry.
  • Amebas: A single-celled organism known as Naegleria fowleri causes amebic meningitis. It lives in soil and water worldwide.
  • Other causes: Cancer, lupus, injury, and certain drugs can cause noninfectious meningitis.

Learn more about contracting meningitis here.

There are many risk factors for meningitis, including:

  • medical disorders such as kidney failure, diabetes, and cystic fibrosis
  • being very young or an older adult
  • not having meningitis vaccinations
  • having a suppressed immune system from having an organ transplant or an immunodeficiency
  • living in a crowded setting
  • traveling or living in an area where meningitis regularly occurs
  • taking certain medications that weaken the immune system, such as steroids and anti-TNF drugs

A doctor diagnoses meningitis by performing a physical exam and discussing any symptoms.

If a doctor thinks a person may have meningitis, they will order tests to determine the cause of the infection. Tests may include:

Learn more about meningitis diagnosis and tests here.

Treatment differs depending on the cause of meningitis.

  • Bacterial meningitis: Doctors tend to treat bacterial meningitis with antibiotics and start the treatment as soon as possible. With some types of bacteria, doctors may also prescribe steroids to help reduce inflammation.
  • Viral meningitis: This may not require treatment as it often goes away on its own in 7–10 days. In some cases, a doctor may prescribe antiviral medications.
  • Fungal meningitis: Doctors tend to prescribe antifungal medications. Some fungal infections require strong doses of these medications intravenously at first.
  • Parasitic meningitis: There is no specific treatment for parasitic meningitis. However, sometimes doctors may prescribe medications to decrease the effects of the parasites on a person’s body.
  • PAM: Several medications are effective in laboratory settings against the organism that causes PAM. However, it is typically fatal; between 2009–2019, 34 people had the disease, and only three people survived.
  • Noninfectious meningitis: Treatment depends on the cause.

How easily meningitis spreads depends on the type.

Viral meningitis does not spread easily from person to person. However, bacterial meningitis spreads quickly between people who share saliva, come in close contact with each other, or sneeze or cough on someone.

Parasitic forms in the U.S. often come from close contact with raccoons or uncooked food, such as fish or snails.

Fungal meningitis frequently affects people with weakened immune systems.

Several vaccinations can help protect against certain forms of bacterial meningitis, including:

A doctor may also recommend starting a dose of antibiotics to help prevent a serious infection when a person comes in contact with someone with meningitis.

There is no vaccination for viral meningitis resulting from non-polio enteroviruses, the most common cause of viral meningitis. Instead, the CDC recommends:

  • washing hands frequently
  • avoiding close contact with a person who is sick
  • disinfecting frequently touched surfaces
  • staying home when sick
  • getting vaccinated against chickenpox, flu, mumps, measles, and rubella (MMR), which can lead to viral forms of meningitis
  • avoiding mosquitoes that may carry infectious blood
  • controlling mice and rats around the house

Amebic meningitis is rare, and a person can prevent contracting it by not getting water in their nose.

Learn more about meningitis vaccinations here.

A person with meningitis may experience complications.

For example, bacterial meningitis may cause:

For parasitic forms, a person may experience trouble with their eyes. In severe cases, a person may also experience:

  • weakness or paralysis
  • coma
  • permanent disability
  • loss of muscle control or coordination

Learn more about some long-term effects of meningitis here.

A person should talk to a doctor if they develop signs or symptoms of meningitis, such as the meningitis rash.

A person should speak with a doctor if they develop unusual symptoms that do not go away after a few days or are severe. A doctor can help rule out other potential causes or diagnose meningitis.

A person’s outlook can vary significantly based on:

  • their age
  • overall health
  • type of meningitis infection

For example, the fatality rate from bacterial meningitis varies between 7–18%, depending on the cause.

According to the CDC, if a person has PAM, they will often die within 5 days of the development of symptoms.

By contrast, a person with viral meningitis will typically recover within 7–10 days.

There are several different types of meningitis, but viral and bacterial are the most common types in the U.S.

Meningitis can develop from various viruses, bacteria, fungus, and parasites.

Symptoms, causes, treatment, and outlook can vary significantly according to the type of infection a person has. Anyone who suspects they have meningitis must seek medical attention as soon as possible.