A previously healthy 65-year-old female presents with headache, fever and altered level of consciousness. A CT Brain scan is normal and an LP is performed showing the following results:

Parameter Patient Value Normal Adult Range
Opening pressure 22 cm H2O* 5 – 15
White Blood Cell Count 240 cells/μL*(75% mononuclear) 0–5
Red Blood Cell Count 1 cell/μL 0–5
Protein 800 mg/L* 150 – 400
Cerebrospinal Fluid Glucose 3.0 mmol/L 2.5 – 4.4
Serum Glucose 6.0 mmol/L 4.2 – 6.9

The patient is currently treated solely with Ceftriaxone 2g 12 hourly.

Give the three most likely infectious causes that would require additional specific treatment, and give the treatment of each of these conditions.

(40% marks)

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College Answer

  • Listeria                               Benzylpenicillin 2.4g Q4H or Ampicillin  2g ivi Q4-6H
  • HSV                                    Aciclovir 10mg/Kg Q8H 
  • Resistant pneumococcus:  Vancomycin load 25-35mg/kg and reasonable ongoing dosing regimen)
  • TB                                       Isoniazid plus rifampicin plus ethambutol plus pyrazinamide
  • Cryptococcus                     Amphotericin

Discussion

This is another one of these "match the bug with an appropriate agent" questions, much like Question 11 from the first paper of 2011 or Question 17.1 from the second paper of 2010.

The only new issue raised in this question (when compared to all the other questions of this sort) is the mention of HSV meningitis requiring 10mg/kg qid of aciclovir, and the naming of all the drugs from the tuberculosis cocktail (isoniazid, rifampicin, ethambutol and pyrazinamide).

Interestingly, in this question the Listeria is managed with benzylpenicillin, whereas a meningitis question from the same paper (Question 11 from the first paper of 2015) lists ampicillin instead.