Fungal Meningitis (10) Flashcards
What is the most common agent in fungal meningitis in immunocompromised patients?
Cyrptococcus neoformans
What population would a fungal meningitis most likely be seen in?
Immunocompromised–> 85% of cases are in HIV-infected patients
What form are cryptococcus always seen in?
always encapsulated yeasts (not dimorphic)
How is cryptococcus n. acquired?
Via inhalation (comes from pidgeon droppings or soil)–> establishes an asymptomatic initial pulmonary infection that subsequently spreads via blood to CNS
What three ways can cryptococcus be identified in the CSF?
- Microscopic identification of yeast forms in CSF
- Antigen detection for fungi in CSF
- Culture of CSF for fungo
What test is used to detect Cryptococcus antigen in the CSF?
Latex agglutination test
What test is used to confirm microscopic presence of Cryptococcus?
India ink–> will see yeast with “halos”
*halos due to the capsule
What medium must Crytococcus n. be cultured on?
Saborad’s agar
What fungus account for most cryptococcal infections of healthy individuals?
Crytptococcus gattii–> found in sub-tropical regions and in US o the west coast
What is treatment for cryptococcosis?
Maximum tolerated doses of amphotericin B + flucytosine
*flucytosine enters the CNS better
What organism is the causative agent of the fungal meningitis outbreaks due to contaminated steroids in Fall 2012?
Exserohilum rostratum–> is a common environmental black mold that rarely causes infection
If steroid-associated fungal meningitis is suspected, what two things should be done to confirm?
- culture of CSF
2. send CSF to CDC for PCR analysis
How do Exderohilim rostratum differ from cryptococcus neoformans morphologically?
Exserohilum r. are branched-looking fungi, not the rounded encapsulated yeast seen with cryptococcus n.
What is treatment for sterioid-associated meningitis due to Exserohilum rostratum?
- IV voriconazole for 3 months
* non-responders or sever cases should receive amphotericin B for 3 mo or more
