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 aureus 70% 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  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