Meningitis

Overview

Meningitis is an inflammation of the meninges, the three membranes that cover the brain and spinal cord. This inflammation is typically caused by an infection, though it can also result from certain medications, cancers, or other inflammatory conditions. The space between these membranes contains cerebrospinal fluid (CSF), which can become infected, leading to increased pressure on the brain and spinal cord.

The severity and urgency of meningitis vary greatly depending on its cause. Bacterial meningitis is a medical emergency that can cause death or permanent disability within hours if untreated. Viral meningitis, while serious, is generally less severe and often resolves without specific treatment. Other forms, including fungal and parasitic meningitis, are less common but can be serious in people with weakened immune systems.

Meningitis can affect anyone but is most common in infants, young children, teenagers, and young adults. College students living in dormitories, military personnel in barracks, and people in other close-quarter environments face higher risk. Early recognition and treatment are crucial, as bacterial meningitis can progress rapidly from initial symptoms to life-threatening complications.

Symptoms

Meningitis symptoms can develop over hours or days. Early symptoms may resemble the flu, making initial diagnosis challenging. The classic triad of symptoms includes fever, headache, and neck stiffness, though not all patients present with all three.

Common Early Symptoms

Additional Symptoms in Adults

• Confusion or difficulty concentrating
• Sensitivity to light (photophobia)
• Sleepiness or difficulty waking
• Lack of appetite or thirst
• Skin rash (in meningococcal meningitis)
• Seizures
• Body aches and muscle pain
• Rapid breathing

Symptoms in Infants and Young Children

Babies and young children may show different symptoms:

• Constant crying or high-pitched cry
• Excessive sleepiness or irritability
• Poor feeding or refusing to eat
• Bulging fontanelle (soft spot on head)
• Stiffness in body and neck
• Inactive or sluggish behavior
• Difficulty waking from sleep

Type-Specific Symptoms

Bacterial Meningitis:

• Rapid onset and progression
• Severe symptoms within hours
• Purpuric rash (doesn't fade under pressure)
• Septic shock symptoms

Viral Meningitis:

• Generally milder symptoms
• Gradual onset over days
• Flu-like symptoms prominent
• Usually no rash

Warning Signs Requiring Immediate Care

• Purple rash that doesn't fade
• Severe confusion or delirium
• Seizures
• Loss of consciousness
• Difficulty breathing
• Severe, uncontrollable headache

Causes

Meningitis can be caused by various infectious agents and, less commonly, by non-infectious factors. The cause determines the severity, treatment approach, and prognosis.

Bacterial Meningitis

The most serious form, requiring immediate treatment:

Common Bacterial Causes by Age

• Newborns: Group B Streptococcus, E. coli, Listeria monocytogenes
• Infants/Children: Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae
• Teens/Young Adults: Neisseria meningitidis, Streptococcus pneumoniae
• Older Adults: Streptococcus pneumoniae, Listeria monocytogenes, Neisseria meningitidis

Viral Meningitis

Most common form, usually less severe:

• Enteroviruses: Cause 85% of viral cases
• Herpes simplex virus: Can cause severe meningitis
• Varicella-zoster virus: Chickenpox/shingles virus
• Mumps virus: Less common due to vaccination
• HIV: Can cause chronic meningitis
• West Nile virus: Mosquito-borne
• Influenza virus: Rare complication

Fungal Meningitis

Rare, mainly affects immunocompromised individuals:

• Cryptococcus (most common fungal cause)
• Histoplasma
• Blastomyces
• Coccidioides
• Candida (in premature infants)

Parasitic Meningitis

• Naegleria fowleri (primary amebic meningoencephalitis)
• Angiostrongylus cantonensis
• Toxoplasma gondii (in immunocompromised)

Non-Infectious Causes

• Cancers: Leukemia, brain tumors, metastases
• Medications: NSAIDs, antibiotics, IV immunoglobulin
• Autoimmune disorders: Lupus, Behçet's disease
• Chemical irritation: From medical procedures
• Head injury or brain surgery:

How Meningitis Spreads

• Respiratory droplets: Coughing, sneezing, close contact
• Direct contact: Kissing, sharing utensils
• Fecal-oral route: Poor hygiene (enteroviruses)
• Mother to baby: During birth
• Through breaks in skin: Head trauma, surgery

Risk Factors

Certain factors increase the likelihood of developing meningitis or experiencing severe complications.

Age-Related Risk

• Infants: Highest risk, especially under 2 months
• Children under 5: Increased risk of bacterial meningitis
• Teenagers and young adults: Risk of meningococcal disease
• Adults over 65: Higher risk of pneumococcal meningitis

Living Conditions

• College dormitories
• Military barracks
• Boarding schools
• Child care centers
• Crowded households
• Prisons

Medical Conditions

• Weakened immune system:
  • HIV/AIDS
  • Cancer and chemotherapy
  • Organ transplant recipients
  • Long-term steroid use
• Missing or damaged spleen: Reduced ability to fight infection
• Diabetes: Increased infection risk
• Chronic kidney or liver disease:
• Sickle cell disease:

Other Risk Factors

• Skipped vaccinations: Major preventable risk factor
• Recent respiratory infection: Weakens defenses
• Head injury or brain surgery: Direct pathway for infection
• CSF leak: From injury or birth defect
• Cochlear implants: Slightly increased risk
• Alcohol use disorder: Weakens immune system
• Travel: To areas with meningitis outbreaks

Pregnancy Considerations

• Increased risk of Listeria meningitis
• Can transmit to baby during birth
• Group B strep screening important
• Certain vaccines contraindicated

Occupational Risks

• Healthcare workers
• Laboratory personnel
• Childcare workers
• Teachers in crowded schools

Diagnosis

Rapid and accurate diagnosis of meningitis is crucial, especially for bacterial meningitis where delays can be fatal. Healthcare providers use a combination of clinical assessment and laboratory tests.

Initial Assessment

• Medical history: Symptoms, onset, exposures, travel
• Physical examination: Vital signs, neurological status
• Classic signs:
  • Brudzinski's sign: Neck flexion causes hip flexion
  • Kernig's sign: Pain with knee extension
  • Nuchal rigidity: Neck stiffness

Lumbar Puncture (Spinal Tap)

The definitive test for meningitis:

• Collects cerebrospinal fluid (CSF) for analysis
• Performed urgently in suspected cases
• May be delayed if signs of increased brain pressure

CSF Analysis Includes:

• Cell count: Elevated white blood cells indicate infection
• Protein levels: Usually elevated in bacterial meningitis
• Glucose levels: Low in bacterial, normal in viral
• Gram stain: May identify bacteria immediately
• Culture: Identifies specific organism
• PCR testing: Rapid identification of pathogens

Blood Tests

• Complete blood count (CBC)
• Blood cultures (before antibiotics)
• C-reactive protein and procalcitonin
• Electrolytes and kidney function
• Coagulation studies

Imaging Studies

• CT scan: Before lumbar puncture if:
  • Signs of increased intracranial pressure
  • Focal neurological deficits
  • Papilledema (optic disc swelling)
  • Altered consciousness
• MRI: More detailed brain imaging if complications suspected
• Chest X-ray: Check for pneumonia (common precursor)

Additional Tests

• Latex agglutination: Rapid antigen detection
• PCR panels: Multiplex testing for multiple pathogens
• Viral cultures: For suspected viral meningitis
• Fungal tests: In immunocompromised patients
• TB testing: If tuberculous meningitis suspected

Differential Diagnosis

Conditions that can mimic meningitis:

• Subarachnoid hemorrhage
• Brain abscess
• Encephalitis
• Severe migraine
• Drug reactions

Treatment Options

Treatment for meningitis depends on the cause and must begin immediately for bacterial meningitis. Delays in treatment can result in permanent brain damage or death.

Bacterial Meningitis Treatment

Immediate Empiric Therapy

Started before test results, based on age and risk factors:

• Neonates: Ampicillin + cefotaxime or gentamicin
• Infants/Children: Vancomycin + third-generation cephalosporin
• Adults: Vancomycin + third-generation cephalosporin
• Older adults/immunocompromised: Add ampicillin for Listeria

Adjunctive Therapy

• Corticosteroids: Reduce inflammation and complications
• Given before or with first antibiotic dose
• Most beneficial in pneumococcal meningitis
• Continued for 2-4 days

Targeted Antibiotic Therapy

Adjusted based on culture results:

• S. pneumoniae: Penicillin G or ceftriaxone
• N. meningitidis: Penicillin G or ceftriaxone
• L. monocytogenes: Ampicillin + gentamicin
• H. influenzae: Third-generation cephalosporin

Viral Meningitis Treatment

• Usually supportive care only
• Rest, fluids, pain relief
• Antiviral therapy for specific viruses:
  • Acyclovir for herpes simplex
  • Ganciclovir for CMV
• Hospital monitoring for complications

Fungal Meningitis Treatment

• Cryptococcal: Amphotericin B + flucytosine
• Long-term fluconazole maintenance
• Treatment duration weeks to months
• Monitor for drug toxicity

Supportive Care

• IV fluids: Maintain hydration and blood pressure
• Fever control: Acetaminophen, cooling measures
• Pain management: Analgesics for headache
• Anti-seizure medications: If seizures occur
• Oxygen therapy: If needed
• Intracranial pressure monitoring: In severe cases

Treatment Duration

• N. meningitidis: 5-7 days
• H. influenzae: 7-10 days
• S. pneumoniae: 10-14 days
• L. monocytogenes: 21 days or longer
• Gram-negative bacilli: 21 days

Complications Management

• Increased intracranial pressure: Mannitol, hypertonic saline
• Hydrocephalus: May need ventricular drainage
• Subdural effusion: Usually resolves spontaneously
• Septic shock: Aggressive fluid resuscitation, vasopressors
• DIC: Blood product replacement

Contact Management

• Close contacts may need prophylactic antibiotics
• Rifampin, ciprofloxacin, or ceftriaxone
• Household members, daycare contacts
• Healthcare workers with direct exposure

Prevention

Many cases of meningitis can be prevented through vaccination and proper hygiene practices. Prevention strategies vary by age group and risk factors.

Vaccines

Meningococcal Vaccines

• MenACWY: Protects against serogroups A, C, W, Y
  • Routine at age 11-12 with booster at 16
  • College freshmen in dorms
  • Military recruits
  • Travelers to endemic areas
• MenB: Protects against serogroup B
  • Ages 16-23 (preferred 16-18)
  • During outbreaks
  • High-risk individuals

Pneumococcal Vaccines

• PCV13: For infants and young children
• PPSV23: For adults 65+ and high-risk groups
• Prevents most serious forms of pneumococcal disease

Haemophilus influenzae type b (Hib)

• Routine childhood vaccination
• Has dramatically reduced Hib meningitis
• Given at 2, 4, 6, and 12-15 months

Other Preventive Vaccines

• MMR: Prevents mumps meningitis
• Varicella: Prevents chickenpox complications
• Influenza: Annual flu vaccine
• BCG: In countries with high TB rates

Hygiene Practices

• Frequent handwashing with soap and water
• Avoid sharing personal items (cups, utensils, lip balm)
• Cover mouth when coughing or sneezing
• Stay home when sick
• Avoid close contact with sick individuals
• Don't smoke (weakens immune system)

For High-Risk Groups

College Students

• Ensure meningococcal vaccination before enrollment
• Consider MenB vaccine
• Practice good hygiene in dorms
• Avoid sharing drinks or cigarettes

Travelers

• Check meningitis risk in destination
• Required vaccination for "meningitis belt" in Africa
• Update routine vaccinations
• Travel medicine consultation

Healthcare Workers

• Stay current with vaccinations
• Use appropriate PPE
• Follow infection control protocols
• Post-exposure prophylaxis when indicated

During Pregnancy

• Avoid unpasteurized dairy (Listeria risk)
• Cook meat thoroughly
• Group B strep screening at 35-37 weeks
• Antibiotics during labor if GBS positive

Community Measures

• Prompt reporting of cases
• Contact tracing and prophylaxis
• Outbreak response protocols
• School exclusion during infectious period
• Public health education

Emergency Warning Signs

Meningitis, especially bacterial meningitis, is a medical emergency. Immediate medical attention can be life-saving. Do not wait to see if symptoms improve.

Call 911 or Go to ER Immediately For:

In Adults and Children

• Sudden high fever with severe headache and stiff neck
• Purple rash that doesn't fade when pressed
• Confusion, difficulty concentrating, or delirium
• Seizures
• Severe sensitivity to light
• Persistent vomiting
• Difficulty breathing
• Loss of consciousness

In Infants

• High-pitched or continuous crying
• Excessive sleepiness or difficulty waking
• Poor feeding or refusing to eat
• Bulging soft spot on head
• Body stiffness or floppiness
• Temperature above 100.4°F (38°C) in babies under 3 months

The Glass Test for Rash

• Press a clear glass against the rash
• If rash doesn't fade, could indicate septicemia
• Requires immediate emergency care
• Don't wait for rash - it may appear late or not at all

Why Immediate Treatment Matters

• Bacterial meningitis can kill within hours
• Early treatment dramatically improves outcomes
• Prevents serious complications
• Antibiotics most effective when started early
• Some damage may be irreversible if delayed

What to Expect at the Hospital

• Immediate assessment and stabilization
• Blood tests and cultures
• Antibiotics often started before confirmation
• Lumbar puncture when safe
• Isolation precautions initially
• Close monitoring in ICU if severe

After Exposure to Meningitis

Contact healthcare provider if you've been exposed to someone with bacterial meningitis:

• Household members
• Daycare contacts
• Anyone with direct contact with oral secretions
• May need preventive antibiotics
• Watch for symptoms for 10 days

Related Conditions

Several conditions are related to or may be confused with meningitis. Understanding these relationships helps with diagnosis and treatment.

Complications of Meningitis

• Hearing loss: Most common serious complication
• Learning disabilities: From brain damage
• Hydrocephalus: Fluid buildup in brain
• Seizure disorders: May be permanent
• Stroke: From blood vessel damage
• Kidney failure: From septic shock
• Limb amputation: From septicemia

Predisposing Conditions

• HIV/AIDS - Increased risk of all types
• Diabetes - Higher infection risk
• Cancer - Especially blood cancers
• Sickle cell disease - Pneumococcal risk
• Primary immunodeficiency

Differential Diagnoses

• Severe migraine
• Tension headache
• Sinusitis
• Influenza
• Drug reactions
• Autoimmune disorders

Frequently Asked Questions

References

1. van de Beek D, et al. Community-acquired bacterial meningitis. Lancet. 2021;398(10306):1171-1183.
2. Centers for Disease Control and Prevention. Meningitis. CDC. 2024.
3. Tunkel AR, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis. 2004.
4. McGill F, et al. Viral meningitis: current issues in diagnosis and treatment. Curr Opin Infect Dis. 2017.
5. World Health Organization. Meningitis Fact Sheet. WHO. 2023.
6. Meningitis Research Foundation. Meningitis and Septicaemia Guide. MRF. 2024.