Pneumonia and Immunosuppression (fungal, opportunists) Flashcards
Histoplasma Capsulatum
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Dimorphic, intracellular(marcophages) yeast form in humans
Transmission
Grows in soil and bird droppings
Replication Cycle
Not mentioned
Disease Presentation
Asymptomatic to respiratory infection with cough chills and chest pain (after intense exposure). AIDS patients can develop PANCYTOPENIA, Mouth/GI ulcers, Skin Rash (pustules, or erythema nodosum)
Pathogenic Mechanism
Not mentioned
Epidemiology
Mississippi and Ohio River Valleys
Treatment
SweatY?
Mortality
10% of AIDS patients that get this disease die
Key findings/Diagnosis
Dx: Tissue biopsy of oval yeast in macrophages, or serology or URINARY Antigen can be used.
CXR: Mediastinal LAD, cavitary lesions
Blastomyces dermatitidis
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Broad Based Budding yeast in human tissue
Transmission
Not mentioned
Replication Cycle
Not mentioned
Disease Presentation
Asymptomatic, 50% will have cough, chest pain, sputum, fever and night sweats that resolves spontaneously. Disseminated disease results in ulcerated granulomatous skin lesions (70%), bone (33%), GU (25%), CNS (10%)
Pathogenic Mechanism
Not mentioned
Epidemiology
Infects BOTH immunocompetent and immunocompromised people
Treatment
Voriconazole (IV) then Voriconazole (PO), amphotericin B in severe dz.
Mortality
Not mentioned
Key findings/Diagnosis
DX: Tissue biopsy with broad-based bud (thick walled)
CXR: variable, lobar or multiple nodules
Coccidioides immitis
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Large spherules filled with endospores
Transmission
Not mentioned
Replication Cycle
Spherules rupture to spread endospores inside the lung
Disease Presentation
Asymptomatic to mild flu-like illness (10%) and erthema nodosum (also a feature of histo.). Disseminated disease seen in 1% which often involves BONE, MENINGES, SKIN.
Pathogenic Mechanism
Not mentioned
Epidemiology
1% of disseminated infections typically ocurrs in African Americans, Filipinos, Women in their 3rd trimester
Treatment
Look at sweaty notes
• (Cross says) Fluconazole for meningitis and amphotericin for disseminated disease
Mortality
Not mentioned
Key findings/Diagnosis
Key finding: EOSINOPHILIA
Dx: Serology, microscopy, Skin test reactivity
Paracoccidioides brasiliensis
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Yeast with multiple buds (pilot wheel appearance)
Transmission
not mentioned
Replication Cycle
not mentioned
Disease Presentation
Mild respiratory infection which can progress with dissemination and develoment of oral, nasal, and facial nodular ulcerated lesions and EXTENSIVE submandibular adenopathy
Pathogenic Mechanism
Not mentioned
Epidemiology
Rural Latin America, especially Brazil
Treatment
• (per Cross) Itraconazole or Amphotericin for severe disease
Mortality
Not mentioned
Key findings/Diagnosis
Dx: Tissue biopsy shows Pilot Wheel (yeast with multiple buds)
Aspergillus
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Acute angle branching MOLD with septate hyphae; Radiating chains of conidia
Transmission
Growth occurs on decaying vegetation
Replication Cycle
Not mentioned
Disease Presentation
- *Hemoptysis** may result from fungal balls forming cavities in the lungs. NEUTROPENIA and people with Hematologic Maligancy have the greatest risk of getting infections characterized by infarction, hemorrhage and necrosis.
- *Allergic infection** may also occur and produce high IgE titer and exectoration of bronchial plugs of brown hyphae
Pathogenic Mechanism
See disease presentation
Epidemiology
Found Worldwide
Severe infection seen in people with Neutropenia and Hematologic Malignancies
Treatment
• (Per Cross) Voriconazole or amphotericin/echinocandins if patients can’t handle vori
• REMOVE the fungus ballas
• ABPA: Steroids and Antifungal Agents
Mortality
Not mentioned
Key findings/Diagnosis
CXR: Halo Sign - ball with a cloudy area around it = focal hemorrhage from aspergillis
Dx: Biopsy and see acute angle branching with septate hyphae
Mucormycosis
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Nonseptate broad hyphae with frequent right angle branching; spores in a sporangium
Transmission
Airbone spores
Replication Cycle
not mentioned
Disease Presentation
Headache and Facial pain. Pneumonia and Cutaneous infections can also be caused by mucor.
Pathogenic Mechanism
Invasive rhinocerebral sinusitis, frontal lobe abscesses that orginates in paranasal sinuses then spreads to the orbit, hardpalate and brain
Epidemiology
DIABETICS, NEUTROPENIA, IRON OVERLOAD, Burns/Surgical wounds, coriticosteroid use
Treatment
Treat the Underlying disorder + debridement + Amphotericin or Posaconazole
Mortality
VERY High
Key findings/Diagnosis
Dx: Biopsy with nonseptate broad hyphae with frequent righ angle branching; spores in a sporangium
Pneumocystis jiroveci
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Ping-Pong Ball silver stain/Foamy on H and E
Transmission
Reservoir unknown
Replication Cycle
not mentioned
Disease Presentation
Dry cough with progressive dyspnea, Hypoxemia (O2 sat. may drop down into the 80’s) accompanied by tachypnea (J-receptors).
Pathogenic Mechanism
Organism DOES NOT invade lung tissue, CD4+ T cells recruit monocytes and macrophages that are responsible for clearing the organism. Invasive infection occurs when CD4 DROPS BELOW 200
Epidemiology
70% of world population has been infected, a Leading cause of DEATH in AIDS pts.
Treatment
PROPHYLAXIS for AIDS pts. with CD4 below 200: TMX-SMX, Dapsone, or Atovaquone
TMX-SMX or Clindamycin/Primaquine, Atovaquone, Pentamidine
Mortality
High in AIDS population
Key findings/Diagnosis
Dx: Cysts found on lung exam/lung biopsy or fluids by bronchoscopy can be visualized using Methenamine Silver, Giemsa stain, or Fluorescent Antibody stain. PCR can also be used.
Cryptococcus neoformans
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Oval budding yeast with Wide Polysaccharide capsule forming a narrow-based bud
Transmission
Soil and bird (pigeon) droppings
Replication Cycle
Not mentioned
Disease Presentation
Most immunocompetent patients will be asymptomatic or have mild respiratory symptoms. AIDS patients will have chest pain, dyspnea, cough, and HEMOPTYSIS
Pathogenic Mechanism
Capsule allows it to cause meningitis
Epidemiology
MOST COMMON LIFE THREATENING DISEASE in AIDS PATIENTS
Treatment
See Sweaty
Mortality
Meninigitis = high rate of mortality in AIDS patients
Key findings/Diagnosis
Dx: Narrow based budding oval yeast
Cytomegalovirus
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Eveloped DNA virus
Transmission
Not mentioned
Replication Cycle
Not mentioned
Disease Presentation
Typically Asymptomatic except in immunosuppressed.
1. Immunosuppressed pt: PNEUMONITIS most typical
2. AIDS patients: COLITIS and RETINITIS (typically NOT pneumonitis)
Pathogenic Mechanism
Enters latent state in monocytes and can be reactivated with cell-mediated immunity is decreased
Epidemiology
Worldwide - 80% of pts. have a titer
Treatment
(Val)Acyclovir
Mortality
Not mentioned
Key findings/Diagnosis
CT: Grown glass appearance
Microscopy: OWL EYE appearance with BOTH nuclear and cytoplasmic inclusions
Norcardia Asteriodes
• Stucture
• Transmission
• Replication Cycle
• Disease Presentation
• Pathogenic Mechanism
• Epidemiology
• Treatment
• Mortality
• Key findings/Diagnosis
Stucture
Aerobic Gram-positive, weakly acid-fast bacteria growing in Thin Filaments
Transmission
found in soil
Replication Cycle
not mentioned
Disease Presentation
Pneumonia with brain abscesses. Cavity formation may lead to empyema
Pathogenic Mechanism
Lung infection often disseminates to brain tissue. In both the lungs and brain N. Asteriodes causes cavity formation and Brain Abscesses
Epidemiology
People with reduced Cell-Mediated Immunity are at the highest risk
Treatment
TMX-SMX; resistance can occur so sensitivities should be performed
Mortality
Not Mentioned
Key findings/Diagnosis
Dx: Gram/Acid-fast stain and culture
