Acute Bacterial Meningitis medical comic

Told as a 'Meningitis Detective Agency' case file, this comic covers acute bacterial (pyogenic) meningitis from nasopharyngeal colonisation to the inflamed subarachnoid space. It explains the clinical red flags, how to collect and read CSF, the Gram stain clues to each suspect, the likely organism at each age and the treatment that must start immediately.

For MBBS, NEET-PG, FMGE, NEXT and USMLE revision.

Acute bacterial meningitis: what the comic covers

High-yield points

Bacterial meningitis is infection of the pia, arachnoid and subarachnoid space; time is brain, so treatment cannot wait.
The classic picture is fever, headache and neck stiffness, with altered consciousness; Kernig's and Brudzinski's signs show meningeal irritation.
Lumbar puncture is the key test: pyogenic CSF has raised pressure, many neutrophils, high protein and low glucose. Send blood cultures too.
Gram stain clues: S. pneumoniae is a Gram-positive lanceolate diplococcus; N. meningitidis a Gram-negative kidney-shaped diplococcus; H. influenzae a pleomorphic Gram-negative coccobacillus; Listeria a short Gram-positive rod with tumbling motility.
N. meningitidis ferments glucose and maltose (N. gonorrhoeae only glucose) and can cause a non-blanching petechial rash and epidemics.
Neonates: Group B Streptococcus, E. coli and Listeria. Children and adults: S. pneumoniae and N. meningitidis. After neurosurgery or head injury: staphylococci and Gram-negative bacilli.
Listeria survives refrigeration, is resistant to cephalosporins and needs ampicillin (with gentamicin).
Empiric treatment: IV ceftriaxone or cefotaxime in adults, adding ampicillin when Listeria is possible; ampicillin plus gentamicin in neonates; dexamethasone as an adjunct. Close contacts of meningococcal cases receive chemoprophylaxis.

Mnemonics from the comic

Gram stain: Purple = positive, pink = negative — and the shapes solve the case.
H. influenzae: The needy satellite visits the S. aureus drive-through for a Five (V) and Ten (X) meal.

Quick questions

What does CSF look like in bacterial meningitis?

Pressure is raised, the fluid is cloudy with many neutrophils, protein is high and glucose is low compared with blood glucose. Viral meningitis usually shows lymphocytes with normal glucose.

Why is ampicillin added for suspected Listeria meningitis?

Listeria monocytogenes is naturally resistant to cephalosporins, so ceftriaxone alone does not cover it. Ampicillin, often with gentamicin, is added for newborns, older adults and immunocompromised patients.

Which organisms cause meningitis in newborns?

Group B Streptococcus (S. agalactiae), Escherichia coli and Listeria monocytogenes.

Is this comic free to read?

The first pages are free to preview. Members read the full comic, and you can sign up free to read one comic in full.

From the blog

Cryptococcal meningitis

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