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
Other diagnostic factors
- high-pitched cry (infants)
- rash
- papilledema
- Kernig sign
- Brudzinski sign
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
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)
Tests to consider
- MRI head
- serum procalcitonin
Treatment algorithm
immunocompetent
immunocompromised
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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