Cryptococcal Meningitis

PATHOGENS

• Yeast-like round fungus, 5-10 µm with polysaccharide capsule
• Epidemiology: found worldwide in soil and therefore impossible to completely avoid; exposure to bird droppings increases risk of infection.
• Most common non-candidal fungal infection in HIV+ pts worldwide
  • Major OI in sub-Saharan Africa, Thailand, India.
  • In U.S. pre-HAART era, 5-8% of HIV+ pts developed cryptococcosis. Dramatically reduced incidence in HAART era.
• Cryptococcus neoformans var. neoformans (serotypes A and D).
• Cryptococcus gattii previously known as cryptococcus neoformans var. gattii (serotypes B and C, rare in HIV). Now classified as separate species.
• Cryptococcus neoformans var. grubii (has been used to designate serotype A).