Respiratory infections

Question 1

what are the types of disease of the respiratory tract and what are the two big categories

Answer 1

Upper Respiratory Tract and Lower Respiratory Tract. Upper = pharyngitis and diptheria. Lower = Pneumonia and tuberculosis (extra-pulmonary)

Question 2

what pathogens cause upper respiratory disease

Answer 2

pharyngitis (S. pyogenes)

diptheria (C. dipetheriae)

Question 3

What pathogens cause lower respiratory disease

Answer 3

pneumonia (1. Strep pneumoniae, Legionella pneumophila, primary M. tuberulosis)
Tuberculosis - M. tuberculosis

Question 4

What is the presentation and offending organism of diptheria

Answer 4

Corynebacterium Diptheria. Presents with fever, malaise and “gray membrane”. ultimately to cardiac and neurological manifestations

Question 5

What causes disease all over the body

Answer 5

the toxin spreads. not the bacteria

Question 6

What is the mechanism of C. diptheria?

Answer 6

the toxin leads to ADP-ribosylation of EF-2 which leads to blockage of protein synthesis. The ultimate ending is cardiac and neurological manifestations

Question 7

how does one prevent diptheria? how does this intervention work

Answer 7

prevention is done by giving the vaccine which is a toxoid vaccine. The tetanus ab will then neutralize the toxin and prevent host damage.

Question 8

How does one treat a diptheria case

Answer 8

use an antitoxin and abx

Question 9

What are the the two types of pneumonia and what is the difference between the two?

Answer 9

typical and atypical. typical (involves a single lobe). atypical (bilateral and is a patchy infiltrate all over the lungs

Question 10

What is the presentation and common pathogens for a typical pneumonia. What about sputum culture

Answer 10

usually a gram+ bacteria that responds to a beta-lactam. easy to culture from the sputum.

It will present acutely and severely (sudden onset)

Common suspects are : S. pneumoniae, S. aureus, H. influenza (this is gram-), and K. pneumoniae (also gram-)

Question 11

What is the presentation and common pathogens for an atypical pneumonia. What about sputum culture

Answer 11

onset is gradual (mild progressing to sever). Not really found in the sputum. generally is a gram negative bug.

common suspects: Legionaire. pneumophila, Mycobacterium. pneumoniae, C. pneumo (?)
resp. viruses.

Question 12

What are risk factors for strep pneumo?

Answer 12

older adults. risk factors of lung dz, smoking, respiratory virus

Question 13

What pathogen is commonly found after infection with influenza?

Answer 13

Staph aureus. It will have a typical pneumonia pattern

Question 14

Describe the presentation of pneumococcal. sputum?

Answer 14

Acute onset fever with pleuritic pain and cough. Sputum will be rust coloured. you will find gram positive cocci in pairs

Question 15

What is a common respiratory bug in immunocompromised hosts and why is this

Answer 15

pseudomona. aeruginosa. It can form a biofilm

Question 16

What immunocompromised states are more prone to p. aeruginosa infection

Answer 16

cystic fibrosis, hospitalized, on a ventilator

Question 17

Describe the look of p. aeruginosa

Answer 17

It is a gram- bacillus

Question 18

What is a biofilm

Answer 18

an aggregate of bacteria that forms and extracellular matris. It makes it resistant to antibiotics and host defenses

Question 19

describe legionella pneumophila on a cellular level

Answer 19

It is an intracellular bacterium that lives within the phagosome. It is a gram negative

Question 20

how many serotypes and how does one dx legionella

Answer 20

There is only 1 serogroup and you can dx via a primary urinary antigen test

Question 21

Descrive the presentation of legionella

Answer 21

non-productive cough, fever, dyspnea. Exposure to misted h20 a fisk factor

Question 22

What are the two types of TB

Answer 22

primary TB and reactivation TB.

Question 23

What determines whether you get latent TB or progressive primary TB

Answer 23

strong immune response which just means that the mycobacterium will persist. weak immune response means they flourish and take over the lung

Question 24

What is characteristic of reactivation TB

Answer 24

Fever, nigh sweats, weight loss. pulmonary cough and cavitation

extrapulmonary manifestations occur in many body sites.

Question 25

Describe the immune response to TB

Answer 25

initially the TB will proliferate unchecked within the phagosomes of macrographages. The initial T-helper cell response will make the macrophages competent to kill of the TB leading to latency and granuloma formation.

when this immune response fails, this will lead to reactivation TB

Question 26

how does one dx TB actively

Answer 26

detection of the bacteria in the sputum during active disease. use an acid-fast stain. Can also use an immune test like ifn-gamma. Can also culture but this takes a long time.

Question 27

how does one detect the latent disease

Answer 27

use a purified protein derivative skin test (PPD) or use the IFN-gamma release assay

Question 28

how does one prevent and treat TB

Answer 28

infection control… that’s about it for prevention. treatment is with multiple drugs for 6-18 months. The therapy is guided by susceptibility test and local resistance patterns. multiple drugs used