Lower Respiratory Infections

Question 1

What are the 3 components of the triad of infectious disease?

Answer 1

1. Host
2. Environment
3. Pathogen

Question 2

What would be considered to fall under the category of “Host”?

Answer 2

1. Anatomic Defenses
2. Innate Immunity
3. Acquired Immunity
   
   • Humoral
   • Cell-mediated

Question 3

What would fall under the category of “environment”?

Answer 3

1. Humans
2. Animals
3. Occupational
4. Travel
5. Setting
6. Inoculum

Question 4

What would fall under the category “pathogen”?

Answer 4

1. Bacteria
2. Mycobacteria
3. Fungi
4. Viruses
5. Protozoa
6. Metazoans

Question 5

What is virulence?

Answer 5

The ability to cause disease

Question 6

What is required for the diagnoses of pneumonia?

Answer 6

Chest X-Ray showing parenchymal infiltrates

Question 7

What are the divisions of Acute pneumonia?

Answer 7

1. Typical
2. Atypical
3. Aspiration
4. Viral

Question 8

Describe Typical Acute pneumonia

Answer 8

1. Community-Acquired usually (CAP)
2. Measured in hours to days
3. Onset with chills, fever and wet cough
4. Lobar consolidation or segmental or sub-segmental bronchopneumonia
5. Pleura often involved giving chest pain with inspiration (pleuritis)
6. Micro-aspiration of upper respiratory tract colonizing bacteria
7. Most often due to Streptococcus pneumoniae

Question 9

Name the 4 points derived from the compilation of US and UK studies on the etiologies of community-acquired pneumonia

Answer 9

1. Pneumococcus most common pathogen
2. Haemophilus has largely disappeared
3. Gram (-) pneumonia is uncommon but consider Klebsiella pneumoniae
4. Viral pneumonia is often seen in children (respiratory viruses) and during influenza epidemics

Question 10

According to US/UK studies, what are the most common pneumonia causing bacteria?

Answer 10

1. Streptococcus pneumonia

2 . Hemophilus influenzae (but its far behind #1)

Question 11

Name two types of atypical pheumonias

Answer 11

1. Walking pneumonia

2. Environmentally acquired acute pneumonias

Question 12

What are the antibiotics required for atypical pneumonias?

Answer 12

Non-beta-lactam antibiotics

Macrolides, Fluroquinolones, teteracyclines

Question 13

What bacteria are involved in Walking pneumonia?

Answer 13

Mycoplamsma pneumoniae and Chlamydophila pneumoniae

Question 14

What bacteria are involved in Environmentally acquired acute pneumonias?

Answer 14

• Legionella pneumophilia
  
  • Coxiella burnetii
  • Chlamydophila psittaci

Question 15

What are some symptoms/characteristics of Aspiration pneumonia?

Answer 15

• Setting: stupor, coma, or seizures
• Focal infiltrates
• Dependent portions of lung
• Oropharyngeal flora

Question 16

What is the microbiology of community acquired aspiration pneumonia?

Answer 16

Community acquired:

• Gram (+)
• Anaerobes (up to 20%)

Question 17

What is the microbio of hospital acquired aspiration pneumonia?

Answer 17

Hospital-acquired:

-Gram (-), S. aureus

Question 18

What might complicate Aspiration Pneumonia?

Answer 18

Chronic pneumonia with lung abscess formation

Question 19

What is involved in the Trans-tracheal aspiration method?

Answer 19

Aspiration taken with needle inserted into the trachea

Question 20

List the 4 types of oral anaerobic bacteria

Answer 20

1. Gram (+) cocci
2. Gram (+) Bacilli
3. Gram (-) cocci
4. Gram (-) bacilli

Question 21

Give an example of Gram + cocci in oral anaerobic bacteria

Answer 21

Peptostreptococcus

Question 22

Give an example of Gram + bacilli in oral anaerobic bacteria

Answer 22

• Actinomyces
  
  • Eubacterium
  • Leptotrichia

Question 23

Give an example of Gram - cocci in oral anaerobic bacteria

Answer 23

Veillonella

Question 24

Give an example of Gram - bacilli in oral anaerobic bacteria

Answer 24

• Fusobacteriuim
  
  • Prevotella
  • Porphyromonas

Question 25

Describe Actinomyces sps.

Answer 25

- Cause of Pulmonary Actinomycosis - Anaerobic/microaerophic GM + bacillus - Oral Flora--Especially carious teeth and gingivitis - Aspiration pneumonia often with unconsciousness - This organism knows no tissue barrier--penetrating infection

Question 26

What medications would you use to treat Pulmonary Actinomycosis (Actinomyces)?

Answer 26

- Requires long term Rx (6-12 mo) | - penicillin IV then PO or clindamycin

Question 27

Name 4 examples of Viral Pneumonia

Answer 27

1. Human respiratory viruses 2. Hantavirus (Sin Nombre V.) 3. Coronavirus (SARS, MERS) 4. Bacterial pneumonia with or in the wake of influenza

Question 28

What are 3 complications of acute bacterial pneumonia?

Answer 28

1. Necrotizing pneumonitis 2. Lung abscess 3. Empyema

Question 29

What is Necrotizing pneumonitis?

Answer 29

Death of lung parenchyma

Question 30

What is a lung abscess?

Answer 30

Excavation of lung parenchyma

Question 31

What is Empyema?

Answer 31

Spread of infection into potential space between parietal and visceral pleura, requires drainage as part of management - Pleural space infection - Invasion from lung parenchyma - Diagnostic thoracentesis - drainage via chest tube hooked to water seal - management critical to prevent lung "entrapment"

Question 32

Give some examples of Human Respiratory viruses

Answer 32

1. Influenza 2. Parinfluenza 3. RSV 4. Adenovirus 5. Metapneumovirus 6. Enterovirus 7. Paraechovirus

Question 33

Give 2 examples of Coronavirus

Answer 33

1. SARS | 2. MERS

Question 34

Describe Chronic Pneumonia

Answer 34

1. Weeks to months--not days 2. Differential diagnosis 3. Many non-infectious diseases 4. NO empiric treatment 5. Requires diagnosis by bronchoscopy or lung biopsy

Question 35

Nodules in the lungs are indicative of what?

Answer 35

Chronic Pneumonia

Question 36

Describe Tuberculosis based on this lecture

Answer 36

1. Slow-growing acid-fast human pathogen 2. Cough generates droplet nuclei 3. Inhaled into alveolar space 4. Replicates relentlessly and spreads to lymph nodes and then systemic circulation 5. Becomes dormant as host cell mediated immunity develops 6. Host at jeopardy for primary and post-primary disease 7. Public health issues

Question 37

In an immunocompromised host, what is required to investigate possible environmental factors for exposure?

Answer 37

Complete history

Question 38

Name the infectious agents that typically cause Chronic Pneumonia

Answer 38

1. Bacteria and Actinomyces (e.g. Anaerobes, nocardia) 2. Mycobacterium (TB) 3. Fungi (cocci, histo, crypto) 4. Protozoa (todo, entamoeba) 5. Metazoa (paragonimus)

Question 39

How can you manage acute pneumonia?

Answer 39

1. In most cases microbial diagnosis is not possible 2. Nevertheless the possible pathogens of acute pneumonia are well established from previous studies going way back in medical history 3. The development of broad-spectrum antibiotics to cover most possible pathogens makes empiric therapy possible in most cases - Exceptions have arisen due to antibiotic resistance including the pneumococcus, the leading pathogen for lobar and bronchopneumonia

Question 40

Name noninfectious causes of chronic pneumonia.

Answer 40

1. Neoplasia 2. Sarcoidosis 3. Vasculitis 4. Chemicals, drug, or inhalation 5. Radiation 6. Recurrent pulmonary emboli 7. Bronchial obstruction (e.g., foreign body) 8. Pulmonary eosinophilia 9. Pneumoconiosis 10. Allergic Alveolitis 11. Idiopathic Causes

Question 41

What are the idiopathic (non infectious) causes of chronic pneumonia?

Answer 41

1. BOOP 2. CIP, UIP, DIP, LIP, GIP 3. Eosinophilic granuloma 4. Lymphangioleiomyomatosis 5. Goodpasteur Syndrome 6. Alveolar proteinosis 7. Pulmonary Hemosiderosis 8. Angiocentric immunoproliferative lesions

Question 42

Don't forget to memorize the different chronic and non-infectious pathogens

Answer 42

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