histoplassma

Question 1

H.
capsulatum var
capsulatum-

Answer 1

-pulmonary &
disseminated
infections
- eastern US
& Latin
America
- Thinner cell
walls; smaller
size(2-4 um

Question 2

H.
capsulatum
var duboisii

Answer 2

• Skin & bone
  lesions
• Tropical
  Africa(“African
  histoplasmosis”)
• Thicker
  walled, larger
  yeasts(8-15um)

Question 3

transmission and risk factors

Answer 3

Found in soil
with high
Nitrogen
content
E.g enriched
with bird or bat
droppings
-Micronidia and
hyphae
aerosolized &
inhaled

Question 4

features

Answer 4

Can grow inside
macrophages → Inc
phagolysosomal pH →
interferes with enzyme
activity & antigen
processing

Question 5

presentation

Answer 5

90% asymptomatic with low
intensity exposure
May mimic TB
High intensity exposure: sx in
most people
- Fever
- Cough
- Chest pain
Disseminates

Question 6

diagnostic

Answer 6

Non capsulated
thick walled &
budding yeast
in alveolar
macrophage