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36 Cards in this Set
- Front
- Back
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characteristics of pneumocystis jiroveci
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unicellular fungi
unable to grow readily in vitro route of inoculation = inhalation |
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who's susceptible to jiroveci?
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HIV (CD4 <200)
corticosteroids immunosuppressive drugs premature/malnourished infants hematologic malignancies collagen vascular disorders |
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Tx of jiroveci?
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TMP/SMX (PO or IV 21 d)
alternative: clindamycin + primaquine; atovaquone; dapsone; IV pentamidine Prednisone for severe disease (to decrease inflammation injury after Tx) |
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jiroveci poor prognostic indicators?
complication? |
non HIV patient (leukemia patients)
resp failure - mech ventilation complication - pneumothorax |
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characteristics of aspergillus
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ubiquitous
A. fumigatus most common human pathogen opportunistic pathogen, almost always in compromised patients ** tendency for vascular invasion |
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clinical features of aspergillus
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low grade fever
hemoptysis new pulmonary infiltrate chest pain cough |
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Dx of aspergillus
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CXT/CT showing cavitation or "halo sign"
culture from bronchial specimens, or lung biopsy serum galactomannan Ag assay (fungal cell wall) histopathology |
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non pulmonary invasive aspergillosis?
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sinusitis. Dx: biopsy
CNS disease. - may occur w/ pulmonary disease. mass lesion w/ cerebral edema skin - disseminated or llocal |
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invasive aspergillosis prognosis/ poor prognostic indicators
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58% survival
poor prog - severe immunosuppression, disseminated or extensive disease, CNS disease |
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invasive aspergillosis - Tx
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reduce immunosuppression
voriconazole (drug of choice) others ampho B voriconazole + caspofungin caspofungin itraconazole |
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characteristics of mucormycosis (zygomycosis)
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widely distributed in the environment
sites of infection (in order of frequency) - rhinocerebral - pulmonary - cutaneous - GI - CNS - other (renal) |
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mucor risk factors
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** diabetic ketoacidosis
neutropenia hematological malignancies iron chelating Tx (deferroxamine) protein - calorie malnutrition burns trauma |
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mucor pathogenesis
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inoculation - inhaled or direct contact w/ abraded skin
spreads via direct invasion (no hem. spread) tendency for vascular invasion |
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Sx, signs of rhinocerebral mucormycosis
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Sx - facial pain, headache, fever
signs - orbital cellulitis, invasion of the palate, black nasal discharge, proptosis, CN deficits |
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other sites of mucormycosis
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pulmonary
cutaneous GI |
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Dx of mucor
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tissue diagnosis - non septate hyphae w/ branching at right angles (wider than aspergillus), vascular invasion
culture may be negative |
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Tx of mucor
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correct underlying risk factor
surgical debridement antifungal - high dose ampho B IV or posaconazole PO |
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prognosis of mucor
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pulmonary disease, extensive involvement
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characteristics of sporothrix schenckii
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dimorphic fungi
widely distributed in environment (esp rose plants) most cases follow scratch or other trauma |
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presentation of sporotrichosis
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cutaneous lesion at site of trauma. may develop additional lesions in lymphatic distribution
less common - chronic septic arthritis, chronic cavitary pneumonia |
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Dx of sporotrichosis
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biopsy and culture
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Tx of sporotrichosis
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Itraconazole 3-6 months
supersaturated potassium iodine solution (SSKI), ampho B |
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what does dematiaceous mean?
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dark colored fungi whose hyphae are pigmented
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what does dimorphic fungi mean?
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can be both hyphae and yeast
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characteristics of cryptococcus
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encapsulated yeast
widely distributed in the environment - found in bird guano route of inoculation - inhalation |
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cryptococcosis risk factors
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HIV
SLE lymphoproliferative disorders cirrhosis sarcoidosis organ transplant steroid therapy .. etc |
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cryptococcosis clinical presentation
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CNS - meningitis (esp in HIV)
pulmonary - pulm. nodeuls (esp non HIV patients), lobar pneumonia, cavitary lesions, hilar adenopathy, miliary pattern disseminated disease - cryptococcemia skin GI |
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in AIDS patient when is cryptococcosis seen?
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CD4 <50 cells/ul
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presentation of cryptococcosis in AIDS patients
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meningitis of subaute course. only 30% present w/ classic meningeal Sx.
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Tx of cryptococcosis in AIDS pts
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lifelong fluconazole
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CSF findings of cryptococcal meningitis?
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elevated opening pressure
lymphocytosis elevated protein |
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Dx of cryptococcal meningitis?
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cryptococcal antigen
india ink - encapsulated yeast fungal culture |
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poor prognosis of cryptococcal meningitis?
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altered mental status
elevated CSF pressure (>400) crypt Ag titer > 1:1024 poor CSF inflammatory response multiple site of infection underlying disease |
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Tx of cryptococcal meningitis
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ampho B +- flucytosine followed by fluconazole
control ICP if >200. via daily LP or lumbar drain . may need ventriculoperitoneal shunt if uncontrollable |
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Dx of cryptococcosis
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tissue biopsy for culture/ pathology
path : encapsulated narrow based budding, irregular yeast - capsule seen on mucicarmine stain serum crypt Ag has lower sensitivity compared to CNS disease |
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Tx of cryptococcosis
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LP to rule out CNS infection
serum Ag pulmonary infection and immunocompetent - fluconazole extra pulm infection and/or compromised host - treat same as meningitis |
