endemic mycoses

Question 1

Endemic mycoses

Answer 1

Histoplasmosis/Histoplasma capsulatum, Blastomycosis/Blastomyces dermatitidis, Coccidioidomycosis/coccidiodes immits, coccidioides posadasii,

natural habitats are confined to specific geographical regions

All the organisms are dimorphic (mold at room temp, yeast in the heat)

Infection route: inhalation, cutaneous lesions can be observed as a result of the dissemination

Can cause infection in both immune comp and healthy
in HIV its really bad and really easy to get

Question 2

Histoplasma capsulatum

Answer 2

infection: histoplasmosis
Morphology: dimorphic, in cold mold exhibiting macro tuberculate conidia and microconidia (the infectious form)
yeast morphology (intracellular (mononuclear phagocytes) narrow bud neck
epidemiology: Mississippi and Ohio river valley, found in soil rich with bird poop, most residents are exposed by the age of 20
Clinical: low inoculum- symptoms low high high (flu like symptoms) if symptoms present occur around 10 days after inhalation (most will resolve on own) HIV will make it bad, disseminated histo is lethal
Lab: microscopy, culture of bone marrow and tissue, serology
Treatment: might not need, itraconazole, and amphotericin B

Question 3

Blastomyces dermatitidis

Answer 3

infection: blastomycosis
morphology: mold in the cold yeast in the heat broad neck
Epidemiology: Histo plus more midwest found in decaying matter
Clinical: 4-6 week incubation time, severity depends on inoculum and immunocomp or not. They might be disseminated lesions are your clue, uncommon in AIDS
Lab: microscopy, mold in cold y in h
Treatment: depend if needed (amphotericin B or itraconazole)

Question 4

coccidiodes immits, coccidioides posadasii

Answer 4

infection: Coccidioidomycosis, Desert Rheumatism, California Fever, desert Fever
immitus: Cali, posadassi: outside Cali
Morphology: dimorphic (m in c, y in h) mold form produces arthroconidia which is the infectious form. Yeast (form endosporulating spherules)
Epidemiology: desert southwest, arthrocondia is greatest in summer (dust) AIDS patients
Clinical: most virulent human mycotic pathogen (you only need to inhale a few before you get sick.) flu symptoms 7-21 days after exposure, allergic reactions, primary disease usually resolves itself (perform a subQ test) certain ethnic groups get it and pregnant ladies get it
without treatment: 90 % will die if disseminated
Lab: microscopy (spherules),