CNS infections in HIV patients

Differential Diagnosis

• Idiopathic (up to 50%)
• HIV encephalitis
• Acute HIV
• Infectious
  • Viral: routine viral causes of meningitis and encephalitits, VZV (common), JC virus, West Nile virus, EBV
  • Bacterial: syphilis (common), Streptococcus pneumonia, Mycoplasma
  • Fungal: cryptococcosis (most common cause of meningitis), histoplasmosis, blastomycosis, coccidiomycosis
  • Mycobacterial: tuberculous meningitis
  • Parasitic: toxoplasmosis, neurocysticercosis
• Non-infectious
  • Primary CNS lymphoma

Investigations

• Lumbar puncture with opening pressure and CSF sent for:
  • Cell count and differential, protein, glucose
  • Gram stain and bacterial culture
  • Cryptococcus antigen lateral flow assay
  • Acid-fast staining and tuberculosis culture
  • Fungal culture? PCR for JC virus, EBV?
  • Cytology and flow cytometry
• MRI brain