Fungal infx of the respiratory tract Flashcards
What is the main factor that dictates whether a host will be infected with a fungus?
Immune status
What is zygomycosis?
a term used to describe a group of relatively uncommon, but potentially fatal infection caused by fungi belonging to the class Zygomycetes
What are the three predisposing factors to zygomycosis?
Immuno suppression
DM
burns
Where are zygomycetes usually found in the environment?
soil, vegetation, fruit,
What are the three fungi genera that are implicated in causing zygomycosis/are zygomycetes?
Rizopus
Absidia
Mucor
What is the organism and disease caused by fungi in the sinuses?
Zygomycetes
Mucormycosis
What is the organism and disease caused by fungi in oral cavity?
Candida
Thrush/ esophagitis
What are the 7 organisms and disease caused by fungi in the lungs?
Histoplasma Blastomyces Paracoccidiodies Coccidioides Crytpococcus Pneumocystis Aspergillus
True or false: infection with zygomycoses are rare in healthy individuals
True
What is the black mold that is found on bread?
Zygomycetes
Zygomycetes (like rhizopus, absidia and mucor) are septate or not? What is their morphology?
Wide, broad, Non-septate
What is the most common clinical presentation of zygomycoses? Who are they usually found in?
Rhinocerebral zygomycosis
DM pts
What are the initial symptoms of rhinocerebral zygomycosis?
Sinusitis / epistaxis,
fevers
Progression of rhinocerebral zygomycosis can lead to what?
AMS, brain death
What is the major predisposing factor to zygomycotic infections?
Immunosuppression / burn pts
How are zygomycoses diagnosed? What are the visual features?
Observation in culture, with broad aseptate hyphae, frequently have right angle
What is the treatment for zygomycoses?
Amphotericin B
What is the most common form of candida that cause infections in humans?
Candida albicans
What is the diagnostic test for candida albicans?
Spoon shaped germ tube
True or false: candida albicans are normal flora on the skin
True
Where is candida albicans usually found in the environment?
Food and fomites
What is the form that candida albicans takes in infections? In the environment?
Pseudohyphal form infection
Environment = yeast
Who gets thrush?
Immunosuppressed
Abx use
What is the clinical manifestation of thrush?
White, cheesy material in the mouth. With diffuse erythema beneath.
What is the treatment for thrush?
Mouth washes of nystatin and azole compounds
How do you diagnose thrush?
Direct observation in mouth and looking at them microscopically
How do all systemic mycoses initially present?
Respiratory infections through spores
Are the fungi that cause systemic mycoses opportunistic?
No, they can cause disease in previously healthy individuals
What is characteristic of the fungi that cause systemic mycoses?
Dimorphic
Where is histoplasmosis most commonly found?
Mississippi and ohio river
What is darling’s disease, cave dwellers disease, or spelunker’s disease?
Histoplasmosis infx
What is the cause of histoplasmosis?
Histoplasma capsultaum
Where is histoplasma found in the environment?
Soil containing bird/bat droppings
How is histoplasmosis inoculated?
inhalation of micro or macoconidia
What do histoplasma look like?
Round bumps around a central circle (turburculate)
True or false: histoplamsa are intracellular agents
True
Where do histoplasma replicate?
Macrophages
How many individuals who are infected with histoplasma shows symptoms?
~5%
What are the symptoms of pulmonary histoplasmosis? Duration?
Mild, flu like symptoms with a dry cough
Self limiting in 2-3 weeks
What causes the smalle, coin-like calcifications in the lungs that are usually incidental findings?
past infections with histoplamosis
What are the signs/symptoms of chronic pulmonary and disseminated histoplasmosis? Who does this occur in?
Fever, night sweats, weight loss. Hepatosplenomegaly, lymphadenopahty
this occurs in immunocompromised people
How do you diagnose histoplasmosis? What are the visual features?
Direct observation of the fungi in macrophages or antibody detection
Lack of distinctive morphology
What is the treatment for histoplasmosis?
Amphotericin B
Where are blastomycosis common?
Ohio river and mississippi
How many hospitalization happen each year d/t balstomycosis?
~1000 / year
Where in the environment can blastomyces be found/
Moist soil, vegetation
What is the visual characteristic blastomyces dermatitidis?
Large yeast, with thick cell walls
What are the symptoms of blastomycosis?
pulmonary symptoms (like flu),
can also cause ulcerative lesions of the skin, bone, and UG tract
How can blastomycosis be acquired?
Inhalation
What is the cough like in blastomycoses? Histomycoses?
Blasto = wet cough
Histo - dry
What are the symptoms of systemic blastomycoses? (3)
Painless skin lesions
Prostate infection
Bone infection
How do you diagnose blastomycosis?
Visual inspection in sputum
What is the treatment for blastomycosis?
Amphotericin B or
Azole compounds
Where are paracoccidioidoides brasiliensis founds geographically?
South america
Why are men more often affected with paracoccidioidomycosis?
Estrogen may inhibit their growth
What are the symptoms of paracoccidioidomycosis?
Pulmonary similar to histoplasmosis abd blastomycosis
How do you diagnose paracoccidioidomycosis? Visual features?
Ships wheel or mickey mouse ears
What is the biggest fungal infection in the US?
Coccidioidomycosis
Where, geographically, is coccidioidomycosis found?
Cali/ AZ
What is the one type of fungal infection that have a mandatory reporting requirement?
Coccidioidomycosis
What is the epidemic pattern of Coccidioidomycosis?
Drough-rain-drought pattern d/t dust blowing around
What are the visual features of Coccidioidomycosis?
arthrohyphae in “a bag of yeast” forming spherules
What is the infectious form of Coccidioidomycosis?
Small hyphae
What is the species of Coccidioidomycosis found in AZ?
Coccidioidomycosis poseadasii
What is the species of Coccidioidomycosis found in cali?
Coccidioidomycosis immitis
Which fungi cause symptoms more often that others?
Coccidioidomycosis
What are the symptoms of Coccidioidomycosis?
Pulmonary infections (fever, cough, night sweats, malaise, CP)
Members of the Zygomtcetes class (e.g. Rhizopus, absidia, and mucor), produce what type of hyphae?
Non septate
What are the two forms that candida albicans can take? When/where do they take these forms?
Yeast = in environment
Pseudohyphae/Hyphal forms = in infx
What is the india ink test positive for?
Crytococcus neoformans
What fungi forms a germ tube?
Candida albicans
Infections with what two forms of fungi are much more common in immunosuppressed individuals?
Pneumocystis
Aspergillus
What are the five fungi that cause systemic mycosis?
- Histoplasma capsulatum
- Blastomyces dermatitidis
- Paracoccidioides brasiliensis
- Coccidioides immitis
- Cryptococcus neoformans
Which of the five fungi that cause systemic mycosis are not dimorphic? What is its form?
Cryptococcus neoformans–capsulated yeast
What is the form that dimorphic fungi take when infecting our tissues? What about in the environment?
Yeasts in tissues
Molds in environment
Which of the five systemic mycoses have a worldwide distribution, as opposed to specific location?
Cryptococcus neoformans
Which fungal infections are intracellular pathogen, and can be diagnosed by observing that the organism lives inside macrophages?
Histoplasmosis
Blastomycosis (larger)
What is the pathogen that causes Chicago’s disease or Gilchrist’s disease?
Blastomycosis
What are the two ways of diagnosing histoplasmosis?
Culture (long time)
Serological ab testing
Which of the systemic mycoses have the potential to disseminate, and cause ulcerative lesions of the skin, bone, and urogenital tract?
Blastomycosis
How can one differentiate Blastomyces dermatitidis from other fungi?
Larger, with very thick cell walls
What are the symptoms of an acute infection of blastomycosis?
Dry cough, other cold like symptoms
What are the symptoms of a chronic infection of blastomycosis?
cough, fever, chills, night sweats
What are the symptoms of a systemic infection of blastomycosis?
Skin lesions
Bone infections
Prostatitis
How do you diagnose Blastomycosis?
Sputum analysis
What is the treatment for blastomycosis?
Amphotericine B if it does not resolve on its own
How does disseminated paracoccidioidomycosis present?
Chronic, cutaneous and mucocutaneous ulcers
How do you diagnose paracoccidioidomycosis?
Direct observation, cultivation, and serology
How does the disseminated form of coccidioidomycosis present?
Infection of bones, joints, skin, and CNS
How does coccidial meningitis differ from bacterial meningitis?
Much more gradual onset
How do you diagnose coccidoidomycosis?
Direct observation (spherules)
Cultivation
Serology
What is the treatment for coccidoidomycosis?
Azole and amphotericin B
What is the leading cause of fungal meningitis?
Cryptococcal neoformans
What is the shape of cyrtpococcal neoformans? Is it dimorphic?
Encapsulated yeast that is NOT dimorphic
Where does cryptococcus neoformans live in the environment?
Bird droppings and soil
What are the pulmonary symptoms of cryptococcal neoformans? What is the sputum like?
Asymptomatic to flu like.
Little sputum production
What are the symptoms of the disseminated disease of cryptococcos neoformans?
Skine and bone lesions
What is the treatment for cryptococcosis?
Long term treatment with amphotericin B and 5-flurocytosine
What does pneumocystis jiroveci (carinii) cause? Who is notorious for developing this disease?
Pneumonia (PCP).
AIDs pts get this
What is the fungus that acts like a parasite?
Pneumocystis carinii
What is the clinical syndrome of PCP? (3 symptoms)
dyspnea, nonproductive cough, fever
How does pneumocystis jiroveci (carinii) spread?
Through the inhalation of cysts
How do you diagnose pneumocystis jiroveci (carinii PCP?
biopsy
What is the treatment for pneumocystis jiroveci (carinii)?
trimethoprim-sulfamethooxazole
True or false: aspergillious always causes disease
Very false– found everywhere, only in immunocompromised pts
What are the two forms of fungi that commonly cause aspergillosis?
A. Fumigatus and A. Flavus
What is significant about how aspergillus grows in our tissues?
Its a mold, not a yeast.
Is aspergillus septate or non-septate?
Septate
Which fungi can form “fungus balls’ in preexisiting cavities in the lungs?
Aspergillus
True or false: aspergillosis in the lungs is usually bilateral?
False–unilateral
Which type of fungus causes space-occupying lesions in the lungs that move as the pt changes position?
ASpergillomas
How does aspergillus cause hemoptysis?
Hyphae infiltrate the blood vessels in the lungs
Who gets aspergillosis?
pts with leukemia, … ANY immunocomprosmied people
True or false: aspergillosis can disseminatie into organs and CNS
True
How do you diagnose aspergillosis?
Obseveation of hyphal elements in sputum or biopsy materal, culture
What is visually characteristic of aspergillosis?
Septate hyphae with 45 degree angles
Which fungi grows Septate hyphae with 45 degree angles?
Aspergillosis
What is the treatment for aspergillosis?
Azole
Echinocandin
Amphtericin B
Which fungi grows as a broad-base, budding yeast in tissue?
Blastomycosis
Which fungi grows as sphereules in tissue?
Coccidoidomycosis
Which fungi grows as an intracellular budding yeast in tissue?
Histoplasmosis
Which fungi grows as a large and multiple, budding yeast in tissue? (mickey-mouse ears)
Paracoccidoidomycosis
Which fungi do not have Hyphae? Which do?
Do = asperillus
Do not = Zygomycosis
You see branched, septate hyphae at 45 degree angles. Diagnosis?
Aspergillosis
You see broad, non-septate hyphae at 90 degree angles. Diagnosis?
Zygomycosis