Lower RT Infections Part 2 Flashcards Preview

Week 6: Pneumonia and Cough > Lower RT Infections Part 2 > Flashcards

Flashcards in Lower RT Infections Part 2 Deck (20):
1

Donut sign

Calcification below the hilum of the lungs on a lateral X ray
From lymphadenopathy

2

2 main diseases caused by mycobacteria

TB
Leprosy

3

When are non-tuberculosis mycobacteria a problem?

In weakened hosts

4

3 properties of TB infection

Slowly replicating
Strictly aerobic
Unique cell wall composition

5

How long is pulmonary TB treatment usually for?

6 months minimun

6

Where in the lungs is TB usually found

Apex
Cavities
Because it is strictly aerobic

7

How is TB transmitted?

Airborne (aerosolized)
Droplet nuclei containing tubercle bacilli are inhaled, enter lungs, and travel to alveoli

8

What cell type is responsible for granuloma formation?

Macrophages

9

Classic pathologic finding in TB disease

Caseating granuloma

10

Primary TB disease

Primary infection consists of a small parenchymal focus that spreads via local lymphatics to regional lymph nodes
Often results in occult, subclinical bacteremia that seeds distant sites
Younger age = higher risk

11

Mantoux Tuberculin Skin Test

Intradermal injection of TB antigen
Positive result (feel a bump) indicates TB infection
Doesn't distinguish latency from active disease
Read 48-72 hours after given
Based on Type 4 hypersensitivity (delayed-type)

12

3 reasons for false positive Tb test

Infection with non-TB mycobacteria
Previous BCG vaccination
Incorrect method of TST administration

13

5 reasons for false negatives for TB test

Cutaneous anergy (no immune response - PID or HIV)
Recent TB infection (2 months)
Very young age
Recent-live virus vaccination
Overwhelming Tb disease

14

Infection vs Disease

Infection depends on exposure history
Risk of disease depends on patient factors

15

2 main classes of viruses that cause resp infections

Double-stranded DNA
Single-stranded (-)sense RNA

16

Influenza virus

Enveloped
ssRNA
- sense
Influenza A causes seasonal infections and pandemics

17

Antigenic drift vs shift

Drift: minor changes in neuraminidase and hemagglutinin
Shift: major rearrangement and mixing with other strains

18

Neuraminidase inhibitors

Prevents virus from being able to leave the cell

19

Adenoviruses morphology

dsDNA virus
Non-enveloped
Icosahedral

20

3 main clinical presentations of adenoviruses

Respiratory tract infections (droplet, URTI)
Gastroenteritis
Conjunctivitus