Cryptococcosis Flashcards
What is a microscopic characteristic of C.neoformans?
Characteristic carbohydrate capsule.
What is the causative organism of cryptococcosis?
Cryptococcus neoformans
Where is C.neoformans commonly found?
In pigeon faeces.
How is the C.neoformans spread?
Via inhalation of infected dust or faeces.
Can C.neoformans be spread from person to person?
No.
What group of people are at particular risk of C.neoformans infection?
Immunocompromised people.
- AIDS
- clinical infection rare in immunocompetent
What are the clinical features of cryptococcosis?
Chronic meningitis.
Painless lesions on skin.
Cryptococcomas in bone.
What is a feature of the chronic meningitis in cryptococcosis?
Spontaneous re missions and exacerbations.
*personality change
What can a cryptococcoma be misdiagnosed as?
Carcinoma of the bone.
What can occasionally happen in immunocompromised individuals who are infected with C.neoformans?
The organisms may hematogenously disseminate to other organs:
- bone
- skin
- CNS
Ways to diagnose cryptococcosis?
CSF analysis
Microscopy
Cell culture
Detection of capsular polysaccharide antigen
What does one look for in CSF analysis?
Protein: normal - increased
Glucose: normal - increased
Cells: increase in lymphocytes
How is C.neoformans detected using microscopy?
Using India ink to stain the CSF > results in negative staining of the polysaccharide capsule (large halo seen).
What specimen needs to be sent to the lab in order to screen for C.neoformans?
CSF
What is the standard treatment for C.neoformans infection?
Amphotericin B followed by fluconazole.
