Meningitis – CID 2004

Meningitis:

  • Inflammation of the meninges surrounding the brain & spinal cord
  • Peak age: 6-12 mo, 90% <5yr
  • Common Organisms
    • 0-4wk: GBS, E Coli, Listeria monocytogenes, Klebsiella
    • 1-23mo: GBS, E Coli, S. Pneumo, N. Meningitidis, H. Influenzae
    • >2yr: S. Pneumo, N. Meningitidis, Listeria Monocytogenes (>50yo + comorbidities)
    • Viral: HSV1/2, VZV, enteroviruses, West Nile
    • Fungal: Cryptococcus, coccidiides
    • Other: Lyme dz, Neurosyphilis, TB

1  In the patient with a non-specific febrile illness, look for meningitis, especially in patients at higher risk (e.g., immuno-compromised individuals, alcoholism, recent neurosurgery, head injury, recent abdominal surgery, neonates, aboriginal groups, students living in residence).

Risk Factors:
  • Lack of immunization against S. penumoniae & H. Influenzae type B
  • hematogenous spread after invasion from a mucosal surface (nasopharynx)
  • Parameningeal focus: Otitis media, infection, sinusitis
  • Penetrating head trauma
  • Anatomical meningeal defects – CSF leaks
  • Prev Neurosurgical procedures, shunts
  • Immunocompromise: corticosteroids, DM, prematurity, asplenia, HIV, hypogammaglobulinemia, complement deficiency
  • Contact with colonized or infected persons – exposures at day care centres, recent travel, household contact
Clinical Features:
  • Classic Triad: fever, neck stiffness, altered mental status (absence doesn’t r/o meningitis)
    • No fever, no neck stiffness, normal mental staus = 99% sensitivity
  • Neonates / children:
    • Hx: Fever or hypothermia, vomiting, lethargy, irritability, poor feeding, diarrhea, respiratory distress, Sz
    • PE: Toxic, bulging anterior fontanelle, respiratory distress / apnea, petechial/purpuric rash, jaundice, omphalitis
  • Older children / adults:
    • Hx: fever, H/A, neck/back pain/stiffness, confusion, n/v, lethargy, photophobia, altered LOC, confusion, Sz,irritability
    • PE: Toxic, ↓LOC, nuchal rigidity, Kernig’s / Bruzinski’s, focal neurological signs, papilledema, petechial/purpuric rash
  • Meningococcal meningitis: petechial rash on lower extremities
  • Signs of Meningismus – BONK
    • Brudzinski’s – flexion of neck = involuntary flexion of the knee + hip
    • Opisthotonos – rigid spasm of the body w/ the back fully arched & heels / head bent back
    • Nuchal rigidity
    • Kernig’s = pain with passive extension of a flexed knee
    • Jolt accentuation (sen 97% spec 60%) = turn head horizontally at 2-3/sec; + = ↑ h/a
  • Neuroexam: papilledema, sz, focal deficit

2  When meningitis is suspected ensure a timely lumbar puncture.

Ix:
  • B/W: CBCD, electrolytes (SIADH), blood C & S
  • LP: LP w/o CT in pt
    • w/o altered LOC,
    • no recent Sz, no Hx of CNS dz,
    • not immunocompromised,
    • <60yr
  • CSF: cloudy in bacterial meningitis
    • opening pressure
    • cell (WBC & RBC) count + differential
    • glucose, protei concentration
    • gram stain, bacterial C&S
  • AFB, fungal C&S, cryptococcal antigen in
    • immunocompromised pt,
    • subacute illness,
    • suggestive travel hx or TB exposure
  • PCR for HSV, VZV, EBV, enteroviruses if viral cause suspected
  • U/A & U C&S in infants, Gram stain + Cx of petechial / purpuric lesions
  • CT, MRI, EEG if focal neurological signs present

3  In the differentiation between viral and bacterial meningitis, adjust the interpretation of the data in light of recent antibiotic use.

CSF profiles
  1. Bacterial meningitis
    • ↓ glucose (<30), ↑↑ protein (>100), WBC 500-10,000/ul – predominant Neutrophils >50%
  2. Viral Meningitis
    • Normal glucose, ↑ protein (50-100), WBC 10-500/ul – predominant Lymphocytes (herpes WBC 10-1000)

4  For suspected bacterial meningitis, initiate urgent empiric IV antibiotic therapy (i.e., even before investigations are complete).

Bacterial meningitis is a medical emergency – don’t delay Abx before CT or LP
  • Isolation with appropriate infection control until 24 hr after Cx-sensitive abx therapy
  • Fluid restrict if any concern for SIADH
  • hearing test after
  • Report to public health
Empiric Tx:
  • <1mo: ampicillin + cefotaxime ± gentamicin IV
  • >1mo: Vancomycin + ceftriaxone IV
    • Add ampicillin IV (or TMP-SMX) if risk factors for Listeria monocytogenes present
      1. >50yo,
      2. alcoholism,
      3. immunocompromised
  • Acyclovir for HSV meningitis
  • Dexamethasone IV within 20minpriortoorwithfirst dose of Abx if >6 weeks
    • ? benefit on prevention of hearing loss

Prognosis

C/I:
  • H/A, Sz, cerebral edema,
  • hydrocephalus, SIADH,
  • residual neurological deficit (especially CN VIII),
  • deafness, death
Mortality:
  • S. Pneumoniae 25%, N. Meningitidis 5-10%, H. influenzae 5%
  • Worse prognosis if
    • extremes of age,
    • delays in dx and tx
    • stupor or coma, Sz, focal neurological signs, septic shock at presentation

5  Contact public health to ensure appropriate prophylaxis for family, friends and other contacts of each person with meningitis.

Prophylaxis: close or household contacts
  1. H. Influenzae – Tx with Rifampin if they live with an inadequately immunized or immunocompromised child <4yr
  2. N. Meningitidis – Ciprofloxacin, rifampin, or ceftriaxone
Prevention – Immunization
  • Children: Immunization against H. influenze (Pentacel), S penumoniae (Synflorix, Prevnar-13), N. Meningitidis (Menjugate / Menactra)
  • Adult: Immunization against N. Meningitidis in selected circumstances: Outbreaks, travel, epidemics & S. Pneumoniae (pneumovax) for high-risk groups
Public healthy Agency of Canada Indications:
  1. Pneumococcal polysaccharide vaccine (Pneumovax)
    • >65
    • <2 with chronic cardio/respiratory/hepatic/renal disorders, asplenia, sickle cell or immunosuppression
  2. Meningococcal C-conjugate vaccine (Menjugate)
    • young adults (not immunized in childhood)
    • Asplenia – Quadraveltn vaccine (Menactra / Menomune) preferred
    • Travellers to high-risk areas – Quadraveltn vaccine (Menactra / Menomune) preferred
    • Military recruits – Quadraveltn vaccine (Menactra / Menomune) preferred
    • Complement, factor D, or properdin deficiency- Quadraveltn vaccine (Menactra / Menomune) preferred

References:
Advertisements
Tagged with: , , , ,
Posted in 62 Meningitis, 99 Priority Topics, FM 99 priority topics, Neuro

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s

Follow Preparing for the CCFP Exam 2015 on WordPress.com
CCFP ExamApril 30th, 2015
The big day is here.
February 2015
M T W T F S S
« Jan   Mar »
 1
2345678
9101112131415
16171819202122
232425262728  
%d bloggers like this: