Fungal Dz Cards Flashcards
Blasto- stages/infective form
Dimorphic: different form in soil (saprophytic mycelial), produces infective spores, transforms to (extracellular) yeast at body temp
Blasto- appearance/size
5-20 um, double refractile wall
Blasto- type of budding
Broad-based
Blasto- environment/location/distribution
River valleys, mid-atlantic and beyond map; humid with acidic, sandy soils near water (FL alkaline) ; pockets, not diffuse
Blasto- transmission/infection
inhalation > puncture/sore contamination with spores; most transform to yeast in lungs (but skin wounds’ infection local until hematogenous spread); lymphatic spread potential but uncommon
Blasto- zoonosis?
No, but common exposure likely; WARN THE LAB! becomes infectious mold at room temp
Blasto- signalment
Dog: young, sporting, male large breed (lifestyle) Cat: young male
Blasto- body response
Cell mediated immunity, pyogranulomatous, phagocytosis ineffective
Blasto- definitive diagnosis
find org on cyto, histo, culture
In blastomycoses, what CS do cats sometimes have that arent mentioned in dogs
GI signs, urinary tract disease, pleural/abdominal effusion.
Endophthalmitis in a young male sporting dog- top ddx
Blasto
Blasto- other dx
serology unreliable (FN common), antigen testing (serum/urine) more effective, x-reaction possible
Blasto- rads
Abnormal in 85%, discrete, round nodular pulm pattern; bone lesions lytic with periosteal rxn and ST swelling around- looks like cancer
Blasto- tx type/duration
Itraconazole (not generic); 2nd- Amphoteracin B; If eye/CNS- fluconazole (may enucleate); min 2-3 m, at least 1-2 m past resolution
Why are false negatives common in blasto serology
Not all patients develop Ab’s
T/F subclinical infections of blasto are common
False
When should you culture for blasto
When infection suspected but cytology negative OR refractory to Tx
Best and worst Px for blasto
Poor- CNS
Guarded- severe pulmonary
Good- just coughing
Tx blasto relapse
2nd full course, resistance uncommon
Crypto- pathologic form
extra-cellular, thin walled, narrow budding (3-5 um) yeast; Smaller than all blasto but with large capsule (up to 30 um),
Crypto- location
Ubiquitous (esp. S. CA), bird excrement
Crypto- zoonosis
Not contagious, cmmon exposure
Crypto- transmission, type of infection
inhalation- nasal/pulm infection most common
What is the most common fungal dz in cats
Cryptococcus
T/F- underlying immunosuppression common in dogs/cats with crypto
F
Crypto- immunity
cell mediated; ineffective phagocytosis bc capsule
How does crypto get into CNS, other extra-pulm sites
Direct extension/local spread through cribiform plate; hematogenous spread via macrophages eat then exocytose
Crypto- cat main 2 CS
nasal d/c and sneezing; ulcerative cutaneous masses (Less common: inflammatory ocular (> primary lesion)
Sneezing cat with bump on nose- dx
Cryptococcus
Crypto- dog CS
Nasal, CNS, ocular most common (skin, kidney, general CS possible)
If rads abnormal in crypto, what signs are seen
Hilar lymphadenopathy, diffuse-miliary pattern
Skull imaging findings - crypto
granuloma filling nose, nasal bone lysis/deformity
Best dx for crypto
Serology- latex agglutination for Agin serum, aq humor, CSF
T/F resistance to antifungals is relatively common in Crypto
T
Nasal or skin crypto- Tx type and duration
Itraconazole; ~8months (1-2 m past CS and negative titers)
CNS or ocular crypto- Tx
Amphoteracin B + flucytosine first, then itra/fluconazole once controlled
Crypto- Px
Skin/nose: fair to good but slow; eye/brain: guarded to grave
Histoplasmosis- fungus type, pathologic form
dimorphic (infective spores in soil, yeast at body temp)
Crypto- fungus type
Dimorphic, fungal form not seen- only yeast;
Histo- pathologic form
Intracellular small (2-4 um) yeast at body temp, thick double wall, broad based budding; smaller than blasto
Histo- transmission
Inhalation (or ingestion)
Histo- zoonosis
No
Histo- signalment
young male sporting, young male cats
Histo- immunity
Cell-mediated, in most system will clear! Dz in high dose or imm-compromised
T/F- subclinical infections with histo are uncommon
F
Histo- CS dogs
Respiratory and GI (LI diarrhea)
Histo- CS cats
profound weight loss, respiratory, SI diarrhea
Dx histo
Intracellular organisms on CBC
