Meningitis – Symptoms and Causes

Overview

Meningitis is an infection that causes swelling of the meninges. These are the protective membranes surrounding the brain and spinal cord. Common symptoms include headache, fever, and neck stiffness.

In the United States, viral infections are the most frequent cause of meningitis. However, bacteria, fungi, and parasites can also trigger this condition. Some cases improve without treatment within weeks, but others can be life-threatening.

Bacterial meningitis requires immediate medical attention and antibiotic treatment to prevent serious complications. If you suspect meningitis in yourself or a family member, seek emergency medical care immediately.

Key facts about meningitis:

• Affects the fluid and membranes around the brain and spinal cord
• Can be caused by viruses, bacteria, fungi, or parasites
• May improve on its own or become life-threatening
• Requires prompt medical attention

Signs to Watch For

Symptoms in People Over Age 2

Early signs of meningitis often resemble flu symptoms but can develop rapidly. For people older than 2 years, watch for these warning signs:

• High fever that comes on suddenly
• Stiff neck with limited movement
• Severe headache that feels different from normal headaches
• Nausea and vomiting
• Mental confusion or trouble focusing
• Seizures, in some cases
• Extreme drowsiness or difficulty waking up
• Discomfort with bright lights
• Reduced appetite or thirst
• Skin rash (particularly with meningococcal meningitis)

Symptoms in Babies and Infants

Meningitis presents differently in babies and very young children. Look for:

• Elevated temperature
• Persistent crying that doesn’t stop with comfort
• Unusual sleepiness or irritability
• Difficulty waking after sleep
• Decreased activity or sluggishness
• Feeding problems, including refusal to eat
• Poor nursing or bottle feeding
• Frequent vomiting
• Bulging fontanelle (soft spot on the baby’s head)
• Stiffness in body and neck movements

When Medical Care Is Needed

Seek immediate medical attention if you notice:

• Any fever accompanied by headache and neck stiffness
• Severe, persistent headache
• Mental confusion or altered awareness
• Repeated vomiting
• Neck pain or inability to touch chin to chest

Fast treatment is crucial, as bacterial meningitis can be life-threatening within days without proper antibiotics. Delayed treatment increases the risk of permanent brain damage.

What Causes Meningitis

Bacterial meningitis occurs when bacteria enter the bloodstream and travel to the brain and spinal cord.

It can also happen when bacteria directly reach the meninges through ear or sinus infections, or skull fractures. In rare cases, certain surgical procedures may cause this condition.

The most common bacteria that cause meningitis include:

Streptococcus pneumoniae

This is the leading cause of bacterial meningitis in infants, young children, and adults in the United States. This bacterium typically causes pneumonia or ear and sinus infections. Vaccines can help prevent this infection.

Neisseria meningitidis

This bacterium causes meningococcal meningitis, which typically begins as an upper respiratory infection.

This contagious infection primarily affects teenagers and young adults, often causing outbreaks in colleges, boarding schools, and military bases.

Vaccines offer protection, but anyone in close contact with an infected person should take precautions.

Haemophilus influenzae type b (Hib)

Once the most common cause of bacterial meningitis in children, widespread vaccination has significantly reduced these cases.

Listeria monocytogenes

This bacterium, found in unpasteurized cheeses, hot dogs, and deli meats, mainly affects pregnant women, newborns, older adults, and those with weakened immune systems.

During pregnancy, it can cross the placenta and may be fatal to the baby in late-term infections.

Viral Meningitis

Viral meningitis is usually milder than bacterial forms and often resolves without specific treatment. In the United States, enteroviruses cause most cases, particularly in late summer and early fall.

Other viruses that can cause meningitis include herpes simplex virus, HIV, mumps virus, and West Nile virus.

Most people recover completely from viral meningitis without treatment. However, rest, fluids, and pain medication help manage symptoms.

Chronic Meningitis

Chronic meningitis involves symptoms that persist for at least four weeks without improvement. The symptoms develop gradually and include headache, fever, vomiting, and mental confusion.

Various factors can cause this form of meningitis. Unlike acute forms, chronic meningitis requires long-term treatment strategies based on the underlying cause.

Fungal Meningitis

Fungal meningitis is rare in the United States. Symptoms develop gradually and worsen over time. People typically get infected by breathing in fungal spores found in soil, decaying wood, and bird droppings.

This form doesn’t spread between people. Cryptococcal meningitis, a common fungal infection, mainly affects people with weakened immune systems, particularly those with AIDS.

Without antifungal treatment, it can be fatal. Even with treatment, fungal meningitis may recur.

Tuberculous Meningitis

This rare but serious complication of tuberculosis (TB) develops slowly over days or weeks. TB spreads easily between people through the air. Treatment requires specialized TB medications for extended periods.

Parasitic Meningitis

Parasites can cause a rare form called eosinophilic meningitis. Other parasitic causes include tapeworm infections in the brain and cerebral malaria. Amoebic meningitis, sometimes contracted while swimming in fresh water, can rapidly become life-threatening.

Most parasites that cause meningitis typically infect animals first. Humans can become infected by consuming contaminated food. Unlike other forms, parasitic meningitis doesn’t spread from person to person.

Other Causes of Meningitis

Non-infectious causes of meningitis include chemical reactions, medication side effects, allergic responses, certain cancers, and inflammatory diseases such as sarcoidosis.

Risk Factors

Several factors can increase the chance of getting meningitis:

• Vaccination Status: People who haven’t received the recommended vaccines face a higher risk of infection.
• Age Groups at Risk:
  • Children under 5 years old more commonly get viral meningitis
  • People under 20 years old have higher rates of bacterial meningitis
• Group Living Environments: Meningococcal meningitis spreads more easily in:
  • College dormitories
  • Military barracks
  • Boarding schools
  • Child care centers
• Pregnancy Concerns: Pregnant women have an increased risk of Listeria infection, which can cause meningitis. This infection may lead to:
  • Miscarriage
  • Stillbirth
  • Early delivery
• Immune System Issues: People with weakened immune systems face a higher risk due to:
  • AIDS
  • Alcohol use disorder
  • Diabetes
  • Immune-suppressing medications

Individuals without a spleen also have a greater risk, though vaccines can help protect them.

Possible Complications

Meningitis can lead to serious problems if not treated quickly. As the infection continues, patients face higher risks of severe issues, including:

• Brain Damage
• Hearing Loss
• Vision Problems
• Memory Difficulties
• Learning Challenges
• Movement Issues
• Seizures

In the most severe cases, meningitis can cause kidney failure, shock, or even death.

Ways to Prevent Meningitis

Meningitis can spread through everyday actions like coughing, sneezing, or kissing. It can also pass between people who share eating utensils, toothbrushes, or cigarettes.

You can take several steps to lower your risk of getting meningitis:

• Wash hands properly: Make this a regular habit, especially before meals and after using the bathroom, being in crowded places, or touching animals. Teach children proper hand-washing techniques.

• Don’t share personal items: Keep drinks, food, straws, eating utensils, lip balms, and toothbrushes to yourself. This helps stop the spread of germs.

• Maintain good health: Build a strong immune system through adequate rest, regular exercise, and a balanced diet rich in fruits, vegetables, and whole grains.

• Practice proper coughing etiquette: Cover your mouth and nose when coughing or sneezing. It’s best to cough or sneeze into your shoulder.

• Take food safety precautions during pregnancy: To avoid listeria infection, cook meats (including hot dogs and lunch meats) to 165°F (74°C). Only eat cheeses made from pasteurized milk.

Protective Vaccines

Vaccination is one of the most effective tools for preventing serious meningitis infections. Consult your healthcare provider about the vaccines suitable for you and your family, considering your age, health conditions, and risk factors.

Hib Vaccine (Haemophilus influenzae type b)

The Hib vaccine is recommended for children starting around 2 months of age. It is also beneficial for certain adults, including those with sickle cell disease, AIDS, or those without a spleen.

PCV15/PCV20 (Pneumococcal Conjugate Vaccine)

The PCV15/PCV20 vaccine is recommended for children under 2 years. It is also for children ages 2–18 who face higher pneumococcal disease risks.

PPSV23 (Pneumococcal Polysaccharide Vaccine)

The PPSV23 vaccine is recommended for all adults over 65. It is also for younger people with weakened immune systems or ongoing health conditions, like:

• Heart disease
• Diabetes
• Sickle cell anemia
• People without a spleen

MenACWY (Meningococcal Conjugate Vaccine)

Age	Recommended Schedule
11–12 years	First dose
16 years	Booster shot
13–15 years	First dose, with booster between 16 and 18 years
16+ years	Single dose, no booster needed

This vaccine is also recommended for:

• High-risk children between 2 months and 10 years
• Children exposed to someone with meningitis
• Unvaccinated people who have been exposed but aren’t sick

MenB (Serogroup B Meningococcal Vaccine)

The MenB vaccine is for people 10 years of age and older with increased risk. This includes those with sickle cell disease, a damaged or removed spleen, complement component deficiency, or those taking certain medications.

It is also for people exposed during outbreaks of serogroup B meningococcal disease.