lecture 13 - Respiratory tract infection

Question 1

Is pharyngitis mostly viral or bacterial in origin?

Answer 1

Viral

Question 2

What bacteria is the most common cause of bacterial pharyngitis?

Answer 2

Streptococcus pyogenes (GAS)

Question 3

What are the symptoms of streptococcus pharyngitis?

Answer 3

sore throat, dysphasia, enlarged lymph nodes, pus on tonsils/pharynx, petechiae on palate, erythema

Question 4

How can a Group A strep infection be diagnosed in the lab?

Answer 4

Gram stain, culture

Question 5

What is the size and arrangement of group A streps?

Answer 5

Gram positive cocci in chains

Question 6

What are the suppurative complications of GAS infections?

Answer 6

otitis media, sinusitis, tonsil abscesses, sepsis

Question 7

What are non-supparative complications of GAS infections?

Answer 7

Immune-mediated disease - rheumatic fever/heart disease, acute glomerulonephritis

Question 8

What antibiotic should be used to treat presentations of GAS pahryngitis?

Answer 8

Amoxicillin/penicillin

Question 9

What bacteria is the most significant cause of otitis media?

Answer 9

Streptococcus pneumoniae

Question 10

What anatomical feature increases the risk for otitis media in children, but doesn’t affect adults?

Answer 10

A shorter, horizontal auditory/Eustachian tube that makes drainage of the the ear more difficult

Question 11

What is pneumonia?

Answer 11

Infection of the lung parenchyma (alveoli) with consolidation

Question 12

What causes alveolar consolidation in pneumonia?

Answer 12

Inflammatory exudate is produced in alveoli in response to infection

Question 13

What type of pathogen most commonly causes pneumonia?

Answer 13

Bacteria

Question 14

What are the 3 key routes of infection of pneumonia?

Answer 14

Inhalation, aspiration, haemotagenous

Question 15

What is the most common route of infection of pneumonia?

Answer 15

Aspiration - the swallowing of secretions into the lungs from the URT or GIT

Question 16

What are the signs/symptoms of typical pneumonia?

Answer 16

Productive cough, yellow/bloody sputum, dyspnoea, fever, chest pain, nausea/vomiting

Question 17

What are the histological findings for alveoli infected with pneumonia?

Answer 17

Fibrin rich inflammatory exudate, loss of alveolar spaces, neutrophil/macrophage infiltration

Question 18

What are the 2 main types of typical pneumonia?

Answer 18

Lobar, bronco-

Question 19

What bacteria most commonly causes lobar pneumonia?

Answer 19

Streptococcus pneumoniae

Question 20

What bacteria most commonly causes bronchopneumonia?

Answer 20

Haemophilus

Question 21

What lung is more commonly affected by lobar pneumonia?

Answer 21

Right lung

Question 22

What is community-acquired pneomonia?

Answer 22

Infectious bacterial typical pneumonia (most commonly lobar) occurring in previously healthy individuals

Question 23

What age groups are most likely to contract atypical pneumonia?

Answer 23

Children/adolescents, elderly (and immunocompromised)

Question 24

What are some of the bacteria that most commonly cause atypical pneumonia?

Answer 24

Mycoplasma pneumoniae, legionella, chlamydia pneumoniae

Question 25

What are some of the risk factors for developing pneumonia?

Answer 25

Intubation/mechanical ventilation, heart/lung disease, abdominal surgery, abnormal lung secretions (e.g. CF), immunosupression

Question 26

What are the laboratory tests used to diagnose bacterial pneumonia?

Answer 26

Sputum culture and staining, PCR for atypical causes

Question 27

What test is used to determine antimicrobial resistance before prescribing antibiotics for bacterial pneumonia?

Answer 27

AST - Antimicrobial sensitivity testing