Paper I
Question
Differences in CSF in pyogenic and tuberculous meningitis.
Answer
| Parameter | Pyogenic (bacterial) meningitis | Tuberculous meningitis |
|---|---|---|
| Appearance | Cloudy/turbid, purulent | Clear or slightly turbid; may form a fibrin web/cobweb clot on standing |
| Cell count | Markedly elevated (often >1000 cells/µL) | Moderately elevated (usually 100–500 cells/µL) |
| Predominant cells | Neutrophils | Lymphocytes (mononuclear predominance) |
| Protein | Markedly elevated | Elevated (moderate to marked) |
| Glucose | Markedly reduced | Reduced (moderate) |
| Gram stain/culture | Positive for causative bacteria | Negative on Gram stain; AFB stain/culture may show M. tuberculosis (low sensitivity) |
| Additional tests | Bacterial antigen tests, culture | CSF adenosine deaminase (ADA) elevated; PCR for M. tuberculosis |