Bacterial meningitis

Disease Description (Causes and Symptoms)

• Summary of definition: Bacterial meningitis is an acute central nervous system infection in which bacteria such as Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Listeria, and Escherichia coli travel through the bloodstream, cross the blood vessel walls, penetrate into the cerebrospinal fluid, and multiply and cause inflammation in the meninges. Meningococcal meningitis is one form of bacterial meningitis.
• Key pathophysiology: Pathogens cross the blood–brain barrier (BBB) through the upper respiratory tract or bloodstream → penetrate into the cerebrospinal fluid → inflammatory response (infiltration of numerous neutrophils, increased protein, decreased glucose) → increased intracranial pressure and cerebral ischemia and brain damage.
• Main symptoms: High fever, severe headache, neck stiffness, nausea and vomiting, altered consciousness (confusion or coma), and seizures. In children and newborns, poor feeding, lethargy, seizures, or fever may be absent.

Treatment Methods

• Emergency principles: If meningitis is suspected, immediately collect blood cultures and start empiric antibiotics without delay (delayed treatment worsens the prognosis). Hospitalization and intensive care management may be necessary depending on severity.
• Empiric antibiotics (adjusted according to age and risk factors):
  • Adults (typically): vancomycin + a third-generation cephalosporin (ceftriaxone or cefotaxime)
  • Older adults, immunocompromised patients, or when Listeria is suspected: add ampicillin to the above combination therapy
  • Newborns: ampicillin + gentamicin or cefotaxime, according to neonatal guidelines
  • After the causative organism is identified, switch treatment according to culture results and antibiotic susceptibility (targeted therapy)
• Adjunctive medications and procedures:
  • Steroids (e.g., dexamethasone): When administered together with the first dose of antibiotics for pneumococcal meningitis, they may reduce hearing loss and neurological complications (follow national guidelines).
  • Seizure management: Benzodiazepines (acute treatment), and anticonvulsants if needed (e.g., levetiracetam, phenytoin).
  • Intracranial pressure management: Elevating the head, osmotherapy (mannitol or hypertonic solution), mechanical ventilation, decompressive surgery, and neurosurgical consultation when necessary.
• Supportive care: Monitoring vital signs (blood pressure, respiration, and body temperature), fluids and electrolyte correction, pain and fever control, and nutritional support.
• Infection control and prevention: If meningococcal meningitis is suspected or confirmed, provide close contacts with prophylactic antibiotics (e.g., rifampin, ciprofloxacin, or a single dose of ceftriaxone) and recommend the relevant vaccines (pneumococcal, Hib, and meningococcal vaccines).
• Precautions (medical care and self-management):
  • Take antibiotics until the course is completed as directed by the doctor.
  • Go to the emergency department immediately if altered consciousness, difficulty breathing, severe vomiting, persistent high fever, or seizures occur.
  • In meningococcal disease, contagiousness may persist until 24 hours after antibiotics are administered; isolation and contact management are therefore necessary.
• Complications: Hearing loss, cognitive or motor impairment, seizures or epilepsy, hydrocephalus, brain abscess, cerebral infarction, and possible death. Early treatment reduces the risk.
• Prognosis: Varies depending on the causative organism, time to treatment initiation, age, underlying conditions, and level of consciousness. Rapid diagnosis and appropriate antibiotic administration improve the prognosis.

Checkpoints Before an Outpatient Visit (Including Example Questions)

• Items to prepare (before visiting a hospital or being transported to the emergency department)
  • A list of medications currently being taken (including prescriptions, OTC medications, and herbal medicines) and allergy information
  • Medical history (especially immunocompromising conditions, surgeries, and chronic diseases) and whether you are pregnant
  • Information about recent contacts (such as a patient with meningococcal disease) or an outbreak in a group setting
  • Recent test results (if possible, blood test results, imaging reports, medical certificates, etc.)
  • Notes on the date symptoms began and their progression (when fever, headache, vomiting, or altered consciousness occurred)
  • Vaccination history (whether pneumococcal, Hib, or meningococcal vaccines were received)
• Example questions at an outpatient clinic or emergency department (for patients and caregivers)
  • When did the symptoms begin? What is the pattern of the fever?
  • Have you recently had an ear or nasal infection, pneumonia, surgery or an invasive procedure, contact with a newborn, or other relevant exposure?
  • What medications are you currently taking? Do you have an allergy to penicillin or antibiotics?

General Example Questions to Ask the Doctor

• What are the possible side effects of this medication (or this antibiotic)?
• How long will treatment take, and how long will hospitalization (or isolation) be necessary?
• What additional tests are needed to prevent complications (hearing loss or neurological abnormalities)?
• When can I return to daily activities (work or school)?

Disease-Specific Example Questions

• Based on my symptoms and test results, which causative organism is most likely? (If necessary, ask about additional tests such as culture or PCR.)
• Which family members or close contacts should receive what prophylactic antibiotics or testing? (This depends on whether there was exposure to meningococcal disease.)