Meningitis 101

Armaan Khalid

What is meningitis? Inflammation of the meninges

Implies undercurrent infection Types of infection

Bacterial Viral Fungal/Parasite

At risk Young/Elderly Immunocompromised Sepsis Cranial trauma

Common causative organisms

Neisseria meningitidis* (serogroup B) Strep pneumoniae* HIb L monocytogenes Group B Strep Gram negative bacilli Staph aureus70% of acute bacterial meningitis outside neonate period

Clinical Features

Meningitic Syndrome Headache Neck stiffness Fever

Other Signs/Symptoms Vomiting Photophobia Rigors Petecchial rash (N meningitidis) Kernig’s & Brudzinski’s sign

Bacterial VS Viral Meningitis

Viral meningitis Usually less prominent signs Duration less acute Self limiting in nature

* Bacterial meningitis may ‘masquerade’ as viral meningitis

Differential Diagnosis

Meningitis Septicaemia Subarachnoid haemorrhage Migraine Mass lesion Malaria

Investigations

FBE, U&E, LFT, BSL, Coag screen CRP, Blood culture Lumbar puncture Whole blood PCR (EDTA sample)

To confirm meningococcal disease CT

Lumbar Puncture

Primary investigation Do not delay empirical Abx to do LP Done @ level of the iliac crest

L3-4 Should feel slight ‘give’ once in

subarachnoid space

When LP is CI

Raised ICP

CI in Lumbar Puncture

Management

Time is of the essence, don’t delay Rx If referred from GP, ensure IV/IM

BenPen 1.2g is given Empirical Abx

Ceftriaxone or Cefotaxime Dexamethasone

0.15mg/kg (max 10mg) QID for 4 days

Mgmt of Bacterial Meningitis

Role of Dexamethasone

Indicated in pt > 3mths w empirical Abx when CSF shows: Frankly purulent CSF WBC count > 1000/microlitre CSF protein > 1g/litre Bacteria on Gram stain

Things to note

Immunisations Make sure you are immunised for

meningococcal (A & C) and HIb Especially impt for college students

Contact tracing Close contacts should be given oral

ciprofloxacin or rifampicin & consider immunisation