Fungal/Parasitic Infections Flashcards
1
Q
Cryptococcus neoformans
A
- encapsulated yeast; not dimorphic
capsule will stain w/ india ink - in soil and pigeon poop; inhaled and goes to CNS
- opportunistic; causes cryptococcal meningitis in AIDS pts
- headache, vomiting, altered mental status, photophobia, ataxia, dementia, coma
- not as common = fever and nuchal rigidity
2
Q
C. neoformans: dx and ts
A
- dx: india ink stain; CSF = inc. protein and WBCs w/ low glucose
- tx for AIDs pts = amphotericin B + flucytosine and have to be on fluconazole for LIFE; if pt is immunocompetent same tx but fluconazole only for 8 weeks
3
Q
Cryptococcus gattii
A
- very rare
- risk factors = steroid use, pulmonary disease
- birds and leaf litter around trees
- tx = amphotericin B
- seen in WA, OR, southern CA
4
Q
Coccidioides immitis
A
- dimorphic fungus in southwest US
- pulmonary pathogen; causes chronic meningitis in IC pts
- dx: CSF = high lymphocytes and protein w/ low glucose
KOH prep of tissue = spherules - tx = fluconazole for life w/ intrathecal amphotericin B
5
Q
Histoplasma capsulatum
A
- dimorphic fungus in OH, MS, MO; bird and bat poop
- dx w/ ELISA of CSF; cultured on Sabroud-dextrose agar
- tx = liposomal amphotericin B
6
Q
Blastomyces dermatitidis
A
- skin infection that can go to meninges
- broad-based budding yeast
- tx = amphotericin B then fluconazole
7
Q
Naegleria fowleri
A
- primary amoebic meningoencephalitis
- soil and fresh water –> swimming/diving into standing water NOT salt water
- can be transmitted via Neti Pot
8
Q
N. fowleri: S&S, dx, tx
A
- S&S of meningitis; could have abnormal smell or taste
- dx usually at autopsy; can do CSF analysis - looks same as bacterial meningitis; negative gram stain; trophozoites in CSF
- tx = amphotericin B; only 8 people have survived
9
Q
Acanthamoeba species
A
- granulomatous amoebic encephalitis, keratitis, disseminated granulomatous disease (usually in IC pts)
- 100% mortality w/in 7-120d
- same symptoms as N. fowleri EXCEPT no altered smell sense
- get it from swimming (w/ contact lenses also)
- seen in IC pts = AIDS, CA, transplant, DM, SLE, steroids
- PE = coma, + Kernig, concurrent skin lesion or pulmonary rales
- dx usually autopsy; CSF = inc. WBCs and protein, low glucose
10
Q
most severe species for malaria?
A
Plasmodium falciparum
11
Q
malaria: general info
A
- transmitted by mosquito
- sub-Saharan Africa
- causes anemia and/or cerebral malaria
- dx by microscopy –> need to see gametocyte part of life cycle
- very drug resistant
12
Q
cerebral malaria
A
- pt seems drunk
- most common cause of death in malaria pts
- coma, altered mental status or multiple seizures
- coma is reversible; cause unknown
13
Q
malaria: dx and tx
A
- blood smears: boomerang, sausage, banana shaped, etc. is what you will see; could also see “ring form”
- tx = chloroquine; IV quinine in severe cases
14
Q
toxoplasmosis
A
- caused by toxoplasma gondii
- # 1 cause = undercooked pork; also fecal-oral transmission from cat feces
- mostly asymptomatic; could have cervical lymphadenopathy, flu-like symptoms
- seen in IC, AIDS pts
- dx = serology - CSF PCR; CSF could be + (WBCs, elevated protein, normal glucose); head CT for cerebral toxo in AIDS pts = ring enhancing lesions
- tx = pyrimethamine and a sulfonamide; TMP-SMX
15
Q
African trypanosomiasis
A
- African sleeping sickness = causes a coma
- Trypanosoma brucei
- vector = tsetse fly
- pt in coma = CSF infected; pt not in coma = still in the blood
- chancre at bite site; causes meningoencephalitis
- dx w/ Giemsa stain
- tx w/ melarsoprol
