Systemic Fungal Diseases 2

Front 1

Causative organism for histoplasmosis?

Back 1

Histoplasma capsulatum

Front 2

What is the non-pathologic form of histoplasma?

Back 2

dimorphic fungus - saprophytic mycelial form in soil produces infective spores

Front 3

pathologic for of histoplasma?

Back 3

body temp changes to yeast form; small yeast intracellular with thick, retractile, double contoured wall and broad-based budding

Front 4

where can histoplasmosis be found?

Back 4

31 states - all regions with tropical and subtropical climates; also found in MS, MO and OH, river valleys, mid-Atlantic states

Front 5

what can Histo be found in?

Back 5

bird/bat excrement and other high nitrogen substrates

Front 6

is histo contagious?

Back 6

no - but common environmental exposure common

Front 7

what species, breeds, ages are most common for histo?

Back 7

Dog - young, male, sporting breeds; Cats - young cats

Front 8

How are animals infected with histo?

Back 8

inhalation or maybe ingestion

Front 9

what happens after inhalation/ingestion of histo?

Back 9

spores transform to yeast at body temp --> yeast engulfed by mononuclear phagocytes and undergo further replication by budding --> hematogeous or lymphatic spread

Front 10

how is histo spread in the body?

Back 10

hematogeous or lymphatic

Front 11

what kind of immunity to histo?

Back 11

cell mediated

Front 12

how do most animals respond to histo infection?

Back 12

immune system rapidly clears infection

Front 13

are subclinical infections common with histo?

Back 13

yes

Front 14

how do animals usually get infected with histo/why can't they fight it off??

Back 14

high infective dose or immunodeficiency - clinical dz noted

Front 15

what's the most common type of inflammation and where with histo?

Back 15

granulomatous inflammation - infected organs

Front 16

clinical signs in dogs of histo?

Back 16

common: anorexia, weight loss, fever, cough, dyspnea, diarrhea (LI); sometimes seen: polyarthritis, peripheral lymphadenopathy, chorioretinitis, CNS dz, skin lesions

Front 17

PE findings for histo in dogs?

Back 17

pale mm, hepatosplenomegaly, icterus, intra-abdominal lymph node enlargement

Front 18

clinical signs in cats for histo?

Back 18

same as dogs + profound weight loss

Front 19

definitive dx for histo?

Back 19

cytological, histopathologic, culture demonstratino of organism

Front 20

can you see histo on a blood smear?

Back 20

occasionally intracellular organisms will be observed in circulating monocytes, neutrophils and rarely eosinophils

Front 21

liver function tests for histo?

Back 21

may be abnormal

Front 22

thoracic rads for histo?

Back 22

abnormal in 85% of cases; diffuse, miliary to nodular interstitial pulmonary pattern; hilar lymphadenopathy sometimes present

Front 23

serology for histo?

Back 23

unreliable - don't use it

Front 24

first choice treatment for histo? what cannot be involved to use this?

Back 24

itraconazole - no CNS or ocular involvement

Front 25

notes about itraconazole?

Back 25

be aware of bioavailability (capsules with food, liquid without food), tissue distribution; expensive; GI side effects relatively common, monitor ALT

Front 26

other medications for histo?

Back 26

Amphotericin B, fluconazole, terbinafin, ketoconazole

Front 27

how long to treat for histo?

Back 27

at least 60-90 days or continue for at least 1-2 months past resolution of measurable signs (e.g. chest films), whichever is longer

Front 28

prognosis for histo with only pulmonary involvement?

Back 28

excellent

Front 29

prognosis for histo with more involvement than just pulmonary?

Back 29

fair to good

Front 30

is resistance common for histo?

Back 30

no

Front 31

what is the causative agent for Coccidioidomycosis?

Back 31

Coccidioides immitis

Front 32

what is the non-pathologic form of coccidioidomycosis?

Back 32

dimorphic fungus - mycelial form in environment with alternating thin and thick walled sections

Front 33

how is coccidioidomycosis fungus spread?

Back 33

break off one at a time and carried by the wind

Front 34

pathologic form of coccidioidomycosis?

Back 34

spherule is large, round, double-walled structure containing multiple endospores

Front 35

where is coccidioidomycosis found?

Back 35

dry warm climates in sandy soil at low elevation - # of cases increases after high rainfall years; CA, NM, AZ, UT, NV, SW Texas ("lower Sonoran life zone")

Front 36

mode of transmission of coccidioidomycosis?

Back 36

inhalation

Front 37

is coccidioidomycosis contagious?

Back 37

no - common environmental exposure is common; everyone in environment has been exposed

Front 38

what type of animals are affected by coccidioidomycosis?

Back 38

young, male dogs

Front 39

what happens in body after inhalation of coccidioidomycosis?

Back 39

phagocytosis + increased CO2 conc. cause arthroconidia to transform into spherule --> endospores divide within spherule where they're protected from immune system --> released into tissues and either effectively phagocytized (self-limiting dz) or disseminate

Front 40

what's the type of inflammation that responds to coccidioidomycosis?

Back 40

neutrophilic inflammation, followed by monocyte, lymphocyte and plasma cell infiltration

Front 41

how do immunocompetent individuals respond to coccidioidomycosis?

Back 41

subclinical infections common; large infecting doses can overwhelm immune system in some cases

Front 42

when does dz develop after infection with coccidioidomycosis?

Back 42

respiratory signs - 1-3 weeks after exposure; disseminated dz - within 4 months of exposure

Front 43

most common clinical signs of coccidioidomycosis in dogs?

Back 43

cough, weakness, lethargy, anorexia, weight loss, fever

Front 44

other clinical signs of coccidioidomycosis in dogs?

Back 44

lameness with painful, swollen bone lesions, localized lymphadenopathy, ocular lesions and skin lesions, diarrhea

Front 45

clinical signs of coccidioidomycosis in cats?

Back 45

skin lesions (even without underlying bone lesions), fever, anorexia, weight loss

Front 46

rads of coccidioidomycosis?

Back 46

hilar lymphadenopathy, diffuse interstitial pattern, pleural effusion

Front 47

bone lesions of coccidioidomycosis?

Back 47

more proliferative than lytic

Front 48

definitive dx of coccidioidomycosis?

Back 48

cytological, histopathologic or culture demonstration of organism

Front 49

false negatives/positives occur with coccidioidomycosis when?

Back 49

serological tests - false negatives early infection, cutaneous, chronic or rapidly progressing acte infection; cytology



serology - false positives - immune complexes or bacterial contaminants in serum cross rxn

Front 50

treatment of coccidioidomycosis without CNS or ocular involvement?

Back 50

itraconazole

Front 51

other meds for treating coccidioidomycosis?

Back 51

fluconazole, terbinafine, ketoconazole, Amphotericin B

Front 52

how long to treat for coccidioidomycosis?

Back 52

at least 60-90 days or at least 1-2 months past resolution of measurable signs, whichever is longer

Front 53

prognosis for coccidioidomycosis with pulmonary involvement?

Back 53

fair to good - 85-90% chance of cure

Front 54

prognosis for bone infections with coccidioidomycosis?

Back 54

incurable

Front 55

overall recovery rate for coccidioidomycosis?

Back 55

~60%

Front 56

do titers remain positive for coccidioidomycosis?

Back 56

yes - for months to years after clinical resolution