Lecture 18 - Infectious Disease of Lung

Question 1

______ pneumonia is considered INTERSTITIAL pneumonitis with alveolar damage, while ______ pneumonia is characterized by an intraALVEOLAR process (alveolar damage is not always present).

Answer 1

Viral –> Interstitial pneumonitis

Bacterial –> intra-alveolar pneumonitis

Question 2

There are 2 phases of consolidation during the response and resolution of Lobar Pneumonia.

The first phase is _______ hepatization. Why is it called this?

The second phase is ______ hepatization. What is this phase characterized by?

Answer 2

Red Hepatization –> so called because of the red, liver-like appearance of the lung from infiltration of PMNs and RBCs.

Grey Hepatization –> characterized by lysis of RBCs and replacement of acute inflammatory cells with chronic (i.e. Macrophages) and fibrin.

Question 3

Bronchopneumonia is characterized by patchy infection located around _____ airways. It is an _______ process, just like Bacterial pneumonia.

What are the three main organisms that cause Lobar and Bronchopneumonia?

Answer 3

Small airways

Intra-alveolar process (NOT Interstitial like Viral pneumonia)

Staph. aureus

H. influenza

Strep. pneumoniae

Question 4

On autopsy, bronchopneumonia presents as red patches that feel like _______ streets as you pass your fingers over it. Remember that ACUTE Bronchopneumonia presents with _______ infiltrate early on.

Answer 4

Cobblestone streets

Patchy

Question 5

If either lobar or bronchopneumonia is left untreated, it can progress to ______ pneumonia, characterized by fever, pleurisy, putrid sputum, and ______ (infection of the pleural space –> mortality at this point is 10-15%).

Answer 5

Necrotizing pneumonia

Empyema

Question 6

TB is transmitted via ______. It can be inactivated, though not necessarily killed with ____, _____, or ______.

Answer 6

Inhalation

Heat, Light, or Drying

Question 7

The hallmark of TB lung infection is Necrotizing granuloma (central Necrosis with surrounding _____ and _____ cells).

Answer 7

Necrotizing granuloma

Histiocytes

Giant cells

Question 8

______ TB most often occurs in Children. It is a peripheral infection with granuloma formation that leads to local _______ dissemination of the bacteria with ______ adenopathy. This combination is termed ______ complex.

Answer 8

Primary TB

Lymphatic dissemination

Hilar adenopathy

Ghon complex

Question 9

______ is better than Histology at identifying the causative agent for infections.

Answer 9

Microbiology

Question 10

What type of stain is used to identify TB?

Answer 10

Acid Fast

Question 11

______ TB is indicative of hematogenous dissemination.

Answer 11

Milliary TB

Question 12

Candida, Blastomyces, H. capsulatum, and Cryptococci are all _____ forms of fungi (look for budding).

Aspergillus, Mucor, Petrolidium, and Penecillium are all _____ forms of fungi.

Answer 12

Yeast

Fillamentous

Question 13

Apergillus is the MOST COMMON laboratory contaminant. It is identified as having _____ angle branching of filaments and septae.

Answer 13

ACUTE angle

Question 14

Mycetomas produce a _____-like substance that destroys adjacent lung tissue over time. However, they are ______ (the way they obtain nutrients) and colonize previously destroyed lung tissue.

Answer 14

Trypsin-like

Saprophytic

Question 15

In which patients are you most likely to see Invasive Apergillosis?

Answer 15

Immunocompromised

Question 16

Allergic Aspergillosis (hypersensitivity reaction causing asthma-like symptoms) is caused by Aspergillus ________.

Answer 16

Aspergillus fumigatus

Question 17

Cryptococcus neoformans is identified by _____ ink stain or _____ stain (the latter stains the wall of the fungus). Which animal’s feces is a reservoir for this organism?

Answer 17

India ink

Mucin

Pigeons

Question 18

If patients with C. neoformans present with headache, what does this suggest?

Answer 18

Hematogenous dissemination to the brain.

Question 19

Which regions are Blastomyces dermatitidis endemic to?

Answer 19

Central and Southern US

Question 20

Blastomyces infection in the lung looks very similar to _____, causing granulomatus lung disease (necrotizing and non-necrotizing granulomas).

Blastomyces will show budding ______ on staining.

Answer 20

TB

Hyphae

Question 21

Coccidiodes immitis (causative agent for valley fever) is endemic to the soil in the _______ US and Mexico (San Joaquin valley). Patients are typically infected after excavation or activities that move soil.

Answer 21

Southwest US

Question 22

Histoplasma capsulatum is another granulomatus lung disease that mimics TB. Look for multiple ______ granulomas on radiography. It is common and worldwide.

Answer 22

Calcified granulomas

Question 23

Pneumocystis jirovecii is an Opportunistic pathogen. It presents like ______ pneumonia bc it is an Interstitial disease. It cannot be _____, so bronchiolar lavage and/or lung biopsy are necessary to diagnose. ______ stain is used to identify it.

Answer 23

Viral pneumonia

Cultured

Silver stain