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Acute bacterial meningitis

What's new

The World Health Organization (WHO) has released a new guideline on meningitis. Lumbar puncture is recommended as soon as possible in suspected acute meningitis, preferably before starting antimicrobial therapy. Routine brain imaging is not recommended but should be performed before lumbar puncture if high-risk features suggest a cerebral space-occupying lesion with midline shift. Initial empiric antibiotic options include IV ceftriaxone and cefotaxime. IV ampicillin or amoxicillin should be added if there are risk factors for L. monocytogenes, and IV vancomycin is recommended in regions with high prevalence of penicillin or third-generation cephalosporin-resistant S. pneumoniae. If ceftriaxone or cefotaxime are unavailable, IV chloramphenicol combined with benzylpenicillin, ampicillin, or amoxicillin is suggested. Adjunctive IV corticosteroids are recommended in non-epidemic settings and during pneumococcal disease epidemics but not during meningococcal disease epidemics. .

Background

Overview

Definition
ABM is an acute inflammation of the meninges, particularly the arachnoid and the pia mater, associated with the invasion of bacteria into the subarachnoid space.
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Pathophysiology
Bacterial meningitis is mostly caused by S. pneumoniae and Neisseria meningitides.
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Disease course
Bacterial invasion to the CNS through the bloodstream or direct access leads to ABM, which causes clinical manifestations of fever, malaise, headache, meningismus, photophobia, phonophobia, vomiting, altered mental status, focal neurological signs (epileptic seizures, or paresis of a limb), and coma.
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Prognosis and risk of recurrence
Bacterial meningitis is associated with a 34% mortality rate.
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Guidelines

Key sources

The following summarized guidelines for the evaluation and management of acute bacterial meningitis are prepared by our editorial team based on guidelines from the World Health Organization (WHO 2025), the German Neurological Society (DGN 2023), the American Cochlear Implant Alliance (ACI Alliance 2022), the Center for Disease Control (CDC 2022,2019), the American Academy of Family Physicians (AAFP 2017), the Infectious ...
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Screening and diagnosis

Diagnosis: as per DGN 2023 guidelines, suspect ABM if a combination of headache, meningism, fever, and impaired consciousness is present. Do not rule out bacterial meningitis in the absence of individual symptoms.
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Diagnostic investigations

Brain imaging: as per WHO 2025 guidelines, do not obtain cranial imaging routinely in patients with suspected acute meningitis.
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  • Blood cultures

  • Serum inflammatory markers

  • ENT evaluation

  • Neuropsychological evaluation

Diagnostic procedures

Lumbar puncture
As per WHO 2025 guidelines:
Perform lumbar puncture as soon as possible in patients with suspected acute meningitis, preferably before initiating antimicrobial treatment, unless specific contraindications or reasons for deferral exist.
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Defer lumbar puncture if cranial imaging is not readily accessible and any concerning features (Glasgow Coma Score ≤ 10, focal neurological signs, cranial nerve deficits, papilledema, new-onset seizures in adults, or a severely immunocompromised state) are identified until these features have resolved. Do not delay treatment when lumbar puncture is deferred.
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  • CSF analysis

Medical management

Setting of care: as per WHO 2025 guidelines, admit or urgently transfer pediatric and adult patients with suspected acute meningitis to an appropriate healthcare facility for further management.
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  • Antibiotic therapy (timing)

  • Antibiotic therapy (empiric antibiotics)

  • Antibiotic therapy (definitive antibiotics)

  • Antibiotic therapy (routes and duration)

  • Adjunctive corticosteroids

  • Other adjunctive treatments

  • Antiviral therapy

  • Management of sinus vein thrombosis

  • Management of ICP

Inpatient care

Monitoring for complications
As per ESCMID 2016 guidelines:
Obtain monitoring for neurologic and systemic complications in patients with ABM. Obtain ancillary testing in case of deterioration and initiate specific treatment when required.
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Consider obtaining ICP/cerebral perfusion pressure monitoring in selected patients, but not as routine management.
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Nonpharmacologic interventions

Fluid intake: as per WHO 2025 guidelines, do not restrict fluid intake routinely in patients with suspected, probable, or confirmed ABM.
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Therapeutic procedures

Intrathecal antibiotics: as per IDSA 2004 guidelines, consider administering intrathecal vancomycin in patients not responding to parenteral antibiotics.
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  • External ventricular drainage

Surgical interventions

Indications for surgery: as per DGN 2023 guidelines, perform rapid surgery to clear the infectious focus in patients with a parameningeal focus of inflammation (such as sinusitis, mastoiditis) detected clinically (such as otitis media) or on CT as a possible cause of bacterial meningitis.
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Specific circumstances

Infants: as per WHO 2025 guidelines, administer ampicillin, cefotaxime, or ceftriaxone IM or IV plus gentamicin IM or IV for at least three 3 as first-choice antibiotic management in young infants aged 0-59 days hospitalized with suspected meningitis.
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  • Patients with cerebral vasculitis

  • Patients with CSF shunt infection (clinical presentation)

  • Patients with CSF shunt infection (evaluation)

  • Patients with CSF shunt infection (shunt removal)

  • Patients with CSF shunt infection (antibiotic therapy)

  • Patients with healthcare-associated ventriculitis and meningitis (clinical presentation)

  • Patients with healthcare-associated ventriculitis and meningitis (diagnostic imaging)

  • Patients with healthcare-associated ventriculitis and meningitis (CSF culture)

  • Patients with healthcare-associated ventriculitis and meningitis (CSF analysis)

  • Patients with healthcare-associated ventriculitis and meningitis (empiric antibiotic therapy)

  • Patients with healthcare-associated ventriculitis and meningitis (definitive antibiotic therapy, Staphylococcus)

  • Patients with healthcare-associated ventriculitis and meningitis (definitive antibiotic therapy, Pseudomonas)

  • Patients with healthcare-associated ventriculitis and meningitis (definitive antibiotic therapy, Acinetobacter)

  • Patients with healthcare-associated ventriculitis and meningitis (definitive antibiotic therapy, Propionibacterium)

  • Patients with healthcare-associated ventriculitis and meningitis (antifungal therapy)

  • Patients with healthcare-associated ventriculitis and meningitis (intraventricular antimicrobial therapy)

Preventative measures

Meningococcal and Hib immunization: as per AAFP 2017 guidelines, offer vaccination for H. influenzae type B and N. meningitidis in individuals in appropriate risk groups to significantly decrease the incidence of bacterial meningitis.
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  • Pneumococcal immunization

  • Post-exposure prophylaxis

Follow-up and surveillance

Repeat lumbar puncture
As per IDSA 2004 guidelines:
Repeat CSF analysis in patients not responding clinically after ≥ 48 hours of appropriate antimicrobial therapy.
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Perform repeated lumbar punctures to document CSF sterilization in neonates with meningitis due to Gram-negative bacilli, because the duration of antimicrobial therapy is determined, in part, by the result.
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  • Rehabilitation

  • Evaluation for long-term sequelae

  • Management of hearing loss

  • Management of seizures

Quality improvement

Public health reporting: as per EFNS 2008 guidelines, report all cases of suspected meningococcal or H. influenzae type B meningitis to the local public health authorities on an urgent basis.
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