Fungal respiratory infections Flashcards
Which fungal pathogens are associated with the sinuses?
Zygomycetes
Which fungal pathogens are associated with the lungs?
- Histoplasma 2. Blastomyces 3. Paracoccidioides 4. Coccidioides 5. Cryptococcus
Which fungal pathogens are associated with the lungs of immunocompromised patients?
- Pneumocystis 2. Aspergillus
What are predisposing factors to zygomycete infection?
- Immunosuppresion 2. Diabetes 3. Burns
What are the properties of zygomycetes?
- Non-septate hyphae 2. Sporangia bearing sporangiophores
What are the clinical symptoms of rhinocerebral zygomycosis?
- Most common form of zygomycosis 2. Primarily in diabetic patients 3. Infection originates in sinuses 4. Extends to neighboring tissues 5. Initial symptoms look like standard sinus congestion 6. Can progress to periorbital area, brain
What is the diagnosis for zygomycoses (mucormycosis)?
- Broad aseptate hyphae in blood vessels 2. Hyphae branch at 90 degrees
What is the treatment for zygomycoses (mucormycosis)?
Amphotericin B
How does candida present in normal flora?
Yeast
How does candida present in tissue?
Hyphal form
What is the clinical presentation for oral candidiasis?
- Diffuse erythema and white patches on surface of buccal mucosa, throat, tongue, gums 2. Plaques can be scraped or wiped to reveal raw erythematous lesion 3. White lesions are composed of yeast and pseudohyphal forms of C. albicans
What is the treatment for oral candidiasis?
Oral formulations of nystatin and azole compounds
What are the properties of systemic mycoses?
- Initially present as respiratory illness 2. Not opportunistic 3. Acquired by inhalation 4. Dimorphic forms are regional, C. neoformans is worldwide 5. All dimorphic except for C. neoformans (encapsulated yeast)
What pathogens are responsible for systemic mycoses?
- Histoplasma capsulatum 2. Blastomyces dermatitidis 3. Paracoccidioides brasiliensis 4. Coccidioides immitis
What are the characteristics of histoplasmosis?
- Endemic to Mississippi river valley and Ohio river valley 2. Caused by histoplasma capsulatum 3. Found in soil (bird and bat droppings) 4. Infection via inhalation of micro or macroconidia
What is the clinical syndrome of histoplasmosis?
- Inhaled fungal spores are phagocytized by pulmonary macrophages and convert to their yeast form 2. Replicates within macrophages 3. Usually asymptomatic (95%)
What are the properties of histoplasmosis?
- Mild flu like illness with dry cough, fever, fatigue 2. Develops several weeks after exposure 3. Improves in 2-3 weeks 4. Self limiting 5. Calcifications of pulmonary lesions common
What are the properties of chronic pulmonary and dissenminated histoplasmosis?
- Typically in immunocompromised individuals 2. More life threatening than normal histoplasmosis 3. Fever, night sweats, anorexia, fatigue, respiratory symptoms 4. Hepatomegaly, splenomegaly, lymphadenopathy possible
What is the diagnosis for histoplasmosis?
- Direct observation (difficult due to small size) 2. Culture (takes a long time) 3. Serology (detect Ab or Ag)