0107100930 - MFM II - Systemic (Endemic) Mycoses (Alley)

1) Blastomycosis (US East of OK)
2) Coccidiodomycosis (C. America, Northern S. America)
3) Histoplasmosis (US East of OK)
4) Paraccidoiidomycosis (SW US and S. America)

dissemination from the lungs (inhalation), geophilic

inhalation of conidia or infectious particles from decaying matter from recreational or occupational exposure. dogs are 10x more susceptible.

50% asymptomatic. pulmonary infection, flu-like symptoms, resembles tuberculosis/lung cancer because pulmonary mass lesions on xray.

cutaneous - diff squamous cell carcinoma. can also disseminate to skin, bone, prostate, liver, spleen, kidney, CNS

Blastomyces dermatitidis

microscopy shows broad-based budding yeast, culture must be done to yeast to Dx

Antifungal (Aphotericin B), surgical

inhalation of arthroconidia, infectious particles, particles are converted to endospore producing spherules in lungs

primary - 60% asymptomatic, hypersensitivity III immune complex formation. secondary - nodules on lungs, ulmonary disease. disseminated - lungs, meninges, bones, skin

saprobic - mycilium form
parasitic - broad based buds

saprobic - mycilium form at cool temps, produce infectious arthroconidia here
parasitic - pherules are produced w/ endopores after infection

Coccidioides immitis found in California
Coccidioides Posadasii outside of California

Microscropy - arthroconidia visible w/ endopores in sputum sample. Culture is dangerous because endospores are very contagious

primary - supportive. secondary and disseminated - antifungal (Amphotericin B)

saprobic - microconidia are inhaled from soil, bat and avian habitats
parasitic - yeast is phagocytized in alveola and suppresses cell-mediated immune response

microconidia are inhaled from soil, bat and avian habitats

depends on concentration of pathogen exposure. pulmonary infection - 90% asymptomatic. self-limited flu-like symptoms.progressive pulmonary histoplasmosis manifest as chronic symptoms w/ apical cavities and fibrosis. disseminated - oral ulcers, hepatosplenomegaly, fever, weight loss, septic shock-like symptoms

Histoplasma capsulatum
Two variations, both thermal dimorphic
Variant capsulatum
Pulmonary and disseminated disease
Eastern US and Latin America
Variant duboisii
Skin and bone lesions
Tropical areas of Africa

Duboisii (African) - less pulmonary involvement, more skin, bone involvement. larger, thick-walled yeast. GIANT cell formation in infected tissue.

Microscopy - sputum, tissue, marrow, CSF shows lots of clustered yeast in GIANT cells. Culture - unique mycilium

spontaneous, antifungal (amphotericin B)

ONLY in men in high humid areas, acidic soil. infection by inhalation or traumatic innoculation and conidia

latent form: asymptomatic, but opportunistic. symptomatic: chronic pulmonary, respiratory, cough, chest pain, nodular lung lesions

any dissemination is rare

Paracoccidioides brasiliensis

anti-fungal (Amphotericin B)

intravenous anti-fungal therapy used more in systemic infectious agents.