(microbiology) respiratory tract infection

Question 1

what is strep throat?

Answer 1

• exudate - cells that have seeped out of the blood
• pus
• sore throat
• dysphagia - hard to swallow
• dysphonia - hard to speak
• 1-5 days

Question 2

what is tonsillitis?

Answer 2

• swollen tonsils
• erythematous
• dysphagia
• dysphonia
• recurrent
• tonsillectomy - rate of mortality because of internal carotid artery

Question 3

what is quincy?

Answer 3

• complication of tonsillitis
• tonsillar abscess
• can be drained - beware the internal carotid artery

Question 4

what is epiglottitis?

Answer 4

cant swallow own spit and start drooling

Question 5

what are the range of lower respiratory tract infections?

Answer 5

• acute bronchitis
• acute exacerbation of chronic bronchitis
• pneumonia
• influenza

Question 6

what is the common cold?

Answer 6

• acute viral infection of the nasal passages
• sore throat
• mild fever
• spread by droplets and formites
• complications: sinusitis, acute bronchitis
• eg adenovirus, rhinovirus (1-5 days) , respiraotry syncytical virus

Question 7

what is acute sinusitis?

Answer 7

• preceded by a common cold
• purulent nasal discharge
• resolves in 10 days
• treatment is mostly viral aetiology but sometimes antibiotics

Question 8

what is diphtheria?

Answer 8

• life threatening due to toxin production
• characteristic pseudo-membrane
• 1-10 days

Question 9

what is acute bronchitis?

Answer 9

• preceded by common cold
• clinical features: productive cough, fever, normal chest exam, normal chest xray, transient (short duration) wheeze
• antibiotics are not indicated

Question 10

what is acute exacerbation of COPD?

Answer 10

• chronic suptum production, bronchoconstriction, inflammation of the airways
• clinical features: usually preceded by upper resp tract infection, increased sputum production, increased suptum purulence, more wheezy, breathless
• on exam: resp distress, wheeze, coarse crackles, may be cyanosed

Question 11

how to manage acute exacerbation of COPD?

Answer 11

primary care: antibiotic eg doxycycline, amoxicillin
bronchodilator inhalers, short course of steroids
refer to hospital if evidence of resp failure
in hospital: measure arterial blood gasses, CXR to look for other diseases, give O2

Question 12

what is the management of community acquired pneumonia?

Answer 12

• antibiotics: amoxicillin, deoxycycline
• oxygen: maintain SaO2 94-98% or 88-92%
• fluids
• bed rest
• no smoking

Question 13

what is mycoplasma pneumonia?

Answer 13

• no cell wall so resistant to beta-lactam antibiotics
• causes protracted paroxysmal cough eg cilial dysfunction
• h2O2 production damages respiratory membranes

Question 14

what is aspiration pneumoia?

Answer 14

need anaerobic cover

Question 15

what is legionalla?

Answer 15

• chest symptoms may be minimal
• GI disturbance is common
• confusion common

Question 16

what is primary influenzal pneumonia?

Answer 16

• seen most during pandemic years
• in young adults
• high mortality

Question 17

what is secondary bacterial pneumonia?

Answer 17

• common in infants, elderly, debilitated, pre-existing disease and pregnant women
• ## cause of mortality

Question 18

what antivirals are used in flu?

Answer 18

• oseltsmivir

- zanamivir

Question 19

what is chlamydia trachomatis?

Answer 19

• an STI which can cause infantile pneumoina

- diagnosed by CPR on urine of mother or pernasal/ throat swabs of child

Question 20

what is chlamydophilia pneumoniae?

Answer 20

• person to person
• mostly mild resp infections
• may be picked up by test for psittacosis

Question 21

what are the main routes of transmission?

Answer 21

• contact
• airborne
• droplets

Question 22

how to control droplet transmission?

Answer 22

• these are large particles > 5 micron, fall to the floor within 2m
• wash hands, PPE, keep door closed,

Question 23

what are the gram positive upper respiraotry tract colonisers?

Answer 23

• a-haemolytic streopococci inc strep pneumoinae
• b-haemyolytic streoptococci = strep pyogens
• strapholococcus areus

Question 24

what are the gram negative upper respiraatory tract coloniers?

Answer 24

• haemoophilus influenzae

- morexella catarrhalis

Question 25

what are the aspects of acute bronchitis?

Answer 25

clinical = infection and inflammation of the bronchi
- productive cough
- normal chest exam and CXR
- 90% viral - preceded by URT infection, normal chest examination and CXR
antibiotics not usually indicated - other include whooping cough

Question 26

what is the microbiology of COPD?

Answer 26

• 30% viral alone, 50% bacterial, 20% ?

- Haemophilus influenzae & Moraxella catarrhalis, Streptococcus pneumoniae, Gram-negatives & others

Question 27

what are the lung defences?

Answer 27

• normally sterile = no ciliary escalator, alveolar lining fluid, surfacant, Ig complement, FFA, AMP
• alveolar macrophages and neutrophils

Question 28

what is typical pneumoina caused by? (community)

Answer 28

streptococcus pneumoniae

Question 29

what is atypical pneumonia caused by? (community)

Answer 29

• mycoplasma pneumoinae, legionella pneumoina, chlamydophila pneumonia, chlamydia psitacci viruses etc

Question 30

what is hospital acquired pneumonia?

Answer 30

• if you are in hospital for more than 3 days

- including ventilator associated pneumonia

Question 31

what are the clinical aspects of community acquired pneumoina?

Answer 31

Cough
Increased sputum
Chest pain
Dyspnoea
Fever
CXR with infiltrates
Acquired in the community

Question 32

what is the pathology of community acquired pneumonia?

Answer 32

Organism reaches lungs > immune activation & infiltration (systemic response) > fluid & cellular build up in alveoli leads impaired gas exchange

Question 33

what is the microbiology of community acquired pneumonia?

Answer 33

Causative organisms:
Streptococcus pneumoniae  = 70%
Atypicals/viruses	=      20%
Haemophilus influenzae =	 5%
Staphylococcus aureus   =    	 4%
Other bacteria .     = 1%

Question 34

what happens when strep pneumonia is in the lab?

Answer 34

becomes partially haemolysied = green/brown colour

Question 35

what are the infections that may be caused by strep pneumonia?

Answer 35

• sinus infection
• ear infection
• invasive pneumococcal disease
• meningitis
• bloodstream infection

Question 36

what is the capsule of strep. pneumonia used for?

Answer 36

• it is a key virulence factor
• anti-phagocytic
• basis for vaccination
• rough strains (avirulent)

Question 37

how do you detect legionalla?

Answer 37

• viral PCR

- not sputum culture

Question 38

what are the treatments of legionella pneumonia?

Answer 38

• clarythromycin, erythromycin,

- quinolones eg levofloxacin

Question 39

do you give amoxicillin for walking pneumonia?

Answer 39

no, as the organism has no cell wall

Question 40

what are the symptoms of walking pneumonia?

Answer 40

• healthy young person otherwise

rash - dark circle

Question 41

what are the clinical aspects of whooping cough?

Answer 41

• acute trachea-bronchitis
• cold like symptoms for 2 weeks
• paroxysal coughing (2 weeks)
• repeated violent exhalations with severe inspiraotry whoop, vomiting common
• residual cough for month of more

Question 42

what is the microbiology of pertussis (whooping cough)?

Answer 42

• bordetella pertussis
• gram negative coccobacillus
• exclusively human pathogen
• vaccine preventable