16 - systemic mycoses

Question 1

(Histoplasmosis)

1. caused by what?
2. found where?
3. what region of USA?

Answer 1

1. histoplasma capsulatum
2. soil
3. mississippi, ohio, and missouri river regions

Question 2

(Histoplasmosis)

1. route of infection?

Answer 2

1. inhalatin of spores, can alo get intenstinal infection from ingestion

Question 3

(Histoplasmosis)

(path)

1. invades lungs - then spreads where?
2. most prevalent in young, sporting breeds

Answer 3

1. mononuclear phagocyte system (spleen, liver)

Question 4

(Histoplasmosis)

(Cx)

1. most common outcome?
2. is acute or chronic pulmonary infection most common?
3. remember that it can also cause granulomatous thickening of the bowel wall
4. also can cause disseminated infection (bone marrow, LN, liver, spleen, peritoneum, eyes, CNS, skin, bone, oral cavity)

Answer 4

1. subclinical infection of the resp tract.
2. chronic

(acute can be deadly)

Question 5

(Histoplasmosis)

(dx)

1. radiographs show what in lungs?

Answer 5

1. diffuse or nodular interstital pulmonary infiltrates

Question 6

(Histoplasmosis)

1. what is the best method for dx?

Answer 6

1. cytology

(organisms are within cytoplasm of macrophages and appear as round to oval structures, surrounded by a clear halo)

Question 7

(Histoplasmosis)

1. tx of choice?

Answer 7

1. itraconazole (4 to 6 months)

Question 8

(blastomycosis)

1. cause?
2. found where?
3. where in USA?

Answer 8

1. blastomyces dermatitidis
2. sandy, acidic soil near water
3. great lakes regions of US

Question 9

(blastomycosis)

1. infection via what?
2. common in dogs, rare in cats

Answer 9

1. inhalation of spores

(focal skin infection can occur by direct contact)

Question 10

(blastomycosis)

(cx)

1. what is present in 85% of cases?
2. disseminated infection often spreads where?

Answer 10

1. pulmonary infection (pyogranulomtous pneumonia)
2. lymph nodes, skin, eyes, and bone

(can also get in CNS, male genitalia, oral or nasal cavities, and abdomen)

Question 11

(blastomycosis)

(dx)

1. what is the most useful tool for diagnosis?

Answer 11

1. cyto (thick-walled extracellular with broad based budding)

Question 12

(blastomycosis)

(dx)

Question 13

(blastomycosis)

1. tx of choice?
2. tx success rate?

Answer 13

1. itraconazole for at least 2 to 3 months

(amphotericin can cause nephrotoxicity, other things are used as well…)

2. 75% (can get blindcess and relapses)

Question 14

(coccidioidomycosis)

1. cause?
2. found where?
3. where in US?

Answer 14

1. coccidioides immitis
2. soil
3. desert like areas of southwest US

Question 15

(coccidioidomycosis)

(Cx)

1. most common?
2. pulm infection characterized by what?

Answer 15

1. subclin pulm infection
2. chronic granulomatous pneumonia

Question 16

(coccidioidomycosis)

Question 17

(coccidioidomycosis)

1. tx of choice?

Answer 17

1. itraconazole or ketoconazole for at least 8 months

(amphotericin B also effective)

Question 18

(crytpococcosis)

1. cause?
2. high conc found where?
3. ruote of infection?

Answer 18

1. crytpococcus neoformans
2. where pigeons roost
3. inhalation

Question 19

(crytpococcosis)

1. what Cx with nasal infection?
2. with disseminated?

Answer 19

1. chronic upper resp signs (sneezing, nasal discharge)
2. look at pic

Question 20

(crytpococcosis)

(dx)

1. best method for dx?

Answer 20

1. cyto or biopsy (check for prominent unstained capsule and budding)

Question 21

(crytpococcosis)

1. tx of choice?

Answer 21

1. fluconazole (good penetration of the eyes and nervous system)

Question 22

(crytpococcosis)

1. prog ok if no CNS involvement