Fungal Pneumonias

Question 1

Endemic dimorphic fungi

Answer 1

Blastomyces dermatitidis, Coccidioides immitis, Histoplasma capsulatum

Question 2

Opportunistic Fungi

Answer 2

Candida, Aspergillus, Mucor, Pneumocystis jiroveci

Question 3

What does endemic dimorphic mean?

Answer 3

Can cause lung infection in healthy and immune suppressed
endemic= found in certain geographic areas
dimorphic= exists in 2 morphological forms: molds and yeasts

Question 4

Histoplasma Capsulatum

Answer 4

soil organism: found in caves, chicken coops, old buildings

Question 5

Geographic Distribution of Histoplasma

Answer 5

central and eastern US- Ohio and Mississippi river valleys

Question 6

Pathogenesis of Histoplasma

Answer 6

phagocytosed by macrophages but not killed, control of intracellular yeast replication depends on Th1 cell activation of macrophages through release of gamma interferon
granulomas form and calcify- reactivated if persons immune is suppressed

Question 7

Diagnosis of Histoplasmosis

Answer 7

Culture of sputum or lung tissue is best
Sabourauds agar
Cytologic evaluation shows yeast within macrophages
Serology- look for antibodies in patients serum
Antigen detection in urine

Question 8

Treatment of Histoplasmosis

Answer 8

Severe= amphotericin B

Mild to moderate= itraconazole

Question 9

Blastomycosis

Answer 9

soil organism, found in decaying vegetation, same patho as Histo, can enter blood and go to skin to form pustular lesions

Question 10

Diagnosis of Blastomycosis

Answer 10

Histo= broad based budding yeasts, Serology

Question 11

Treatment of Blastomycosis

Answer 11

Ampho B for serious, itraconazole for mild disease

Question 12

Where is Coccidiodomycosis found?

Answer 12

Southwest US, associated with burrows of desert animals, grows from rain and spreads by wind
50% of people in endemic area have serologic evidence

Question 13

Pathogenesis of Coccidiodomycosis?

Answer 13

formation of spherule containing endospores- spherules resist phagocytosis, endospores can be released and produce extrapulmonary disease

Question 14

Clinical manifestations of Coccidiodomycosis?

Answer 14

acute pulmonary infections AKA valley fever, usually presents with flu like illness with fever, cough, headaches, rash, and myalgia (can widespread to skin, meninges, joint, and bones)

Question 15

Diagnosis of Coccidiodomycosis?

Answer 15

Culture of fluid from any involved site (grow on media in few days)

Question 16

Treatment of Coccidiodomycosis?

Answer 16

ampho B or itraconazole

Question 17

Candida Albicans

Answer 17

part of normal flora of nasopharynx, skin, vagina

Causes infection in: T cell immune suppression, antibiotic therapy, insertion of catheter, neutropenia

Question 18

Diagnosis and Treatment of Candida Albicans

Answer 18

culture of blood or biopsied lung tissue - blood agar or Sabourauds
Treatment= ampho B or echinocandins

Question 19

Aspergillus

Answer 19

ubiquitous, found in damp places in buildings

At risk people: neutropenic, transplant patients, patients on long term corticosteroids

Question 20

Aspergillus manifestations?

Answer 20

sinusitis and pneumonia, can invade blood vessels to disseminate leading to necrotic skin lesions and brain abscesses

Question 21

Diagnosis of aspergillus

Answer 21

Histo= acutely branching septate hyphae, may also see fruiting bodies
diagnosed by sabourauds agar

Question 22

Treatment of Aspergillus

Answer 22

Voriconazole - new standard, Amphotericin B, Caspofungin

Question 23

Pneumocystic jiroveci

Answer 23

may be part of normal flora, inhaled, most individuals may acquire it by 3 yrs
At risk: CD4 cell count less than 200, severely T cell immune suppressed patients

Question 24

Pathogenesis of P. jiroveci

Answer 24

extracellular pathogen controlled activated phagocytic macrophages
replicates in the surfactant layer above the alveolar epithelium - forms trophozites and cysts
damage to basement membrane occurs- reduced o2 exchange

Question 25

Diagnosis of P. Jiroveci

Answer 25

examination of BAL fluid stained with Giemssa, toluidine blue, methenamine silver
thin walled trophozoites and thick walled cysts (4-8 nuclei)

Question 26

Treatment of P. Jiroveci

Answer 26

TMP/SMX