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Bacterial meningitis

Last reviewed: 1 Nov 2024
Last updated: 01 Nov 2024

Summary

Definition

History and exam

Key diagnostic factors

  • headache
  • neck stiffness
  • fever
  • altered mental status
  • confusion
  • photophobia
  • vomiting
  • seizures
  • hypothermia (infants)
  • irritability (infants)
  • lethargy (infants)
  • poor feeding (infants)
  • apnea (infants)
  • focal neurologic deficit
  • abnormal eye movement
  • facial palsy
  • balance problems/hearing impairment
  • bulging fontanel in infants
Full details

Other diagnostic factors

  • high-pitched cry (infants)
  • rash
  • papilledema
  • Kernig sign
  • Brudzinski sign
Full details

Risk factors

  • age ≤5 or ≥65 years
  • crowding
  • exposure to pathogens
  • nonimmunized infants
  • immunodeficiency
  • cancer
  • asplenia/hyposplenic state
  • cranial anatomic defects
  • cochlear implants
  • contiguous infection
  • smoking
Full details

Diagnostic tests

1st tests to order

  • cerebrospinal fluid (CSF) cell count and differential
  • CSF protein
  • CSF glucose
  • CSF Gram stain
  • CSF culture
  • antigen detection in CSF
  • blood culture
  • CBC and differential
  • CRP
  • electrolytes, calcium (Ca), magnesium (Mg), glucose
  • coagulation profile (prothrombin time, INR, activated PTT, fibrinogen, fibrin degradation products)
  • CT head
  • polymerase chain reaction (PCR)
Full details

Tests to consider

  • MRI head
  • serum procalcitonin
Full details

Treatment algorithm

INITIAL

immunocompetent

immunocompromised

ACUTE

confirmed infection: Streptococcus pneumoniae

confirmed infection: Haemophilus influenzae

confirmed infection: Streptococcus agalactiae (group B streptococci)

confirmed infection: Escherichia coli and other gram-negative Enterobacteriaceae

confirmed infection: Listeria monocytogenes

confirmed infection: Staphylococcus aureus

confirmed infection: Staphylococcus epidermidis

confirmed infection: Pseudomonas aeruginosa

confirmed infection: Enterococcus species

confirmed infection: Acinetobacter species

confirmed infection: Neisseria meningitidis

Contributors

Authors

Rodrigo Hasbun, MD, MPH

Professor of Medicine

UT Health Mc Govern Medical School

Houston

TX

Disclosures

RH has received research support and personal fees from Biomeriaux.

Omaima El Tahir, MD

PhD Candidate

Department of Pediatric infectious Diseases and Immunology, AI&II

Amsterdam UMC, Vrije Universiteit Amsterdam

Amsterdam

The Netherlands

Disclosures

OET declares that she has no competing interests.

Acknowledgements

Dr Rodrigo Hasbun and Omaima El Tahir would like to gratefully acknowledge Dr Marceline Tutu van Furth, previous contributor to this topic.

Disclosures

AMTvF declares that she has no competing interests.

Peer reviewers

Guy Thwaites, MA, MBBS, PhD, MRCP, FRCPath

Wellcome Trust Clinical Research Fellow

Centre for Molecular Microbiology and Infection

Imperial College London

London

UK

Disclosures

GT declares that he has no competing interests.

Wendy Ziai, MD, MPH

Assistant Professor

Neurology, Neurosurgery, and Anesthesiology and Critical Care Medicine

The Johns Hopkins University

Baltimore

MD

Disclosures

WZ declares that she has no competing interests.

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