(microbiology) respiratory tract infection Flashcards
1
Q
what is strep throat?
A
- exudate - cells that have seeped out of the blood
- pus
- sore throat
- dysphagia - hard to swallow
- dysphonia - hard to speak
- 1-5 days
2
Q
what is tonsillitis?
A
- swollen tonsils
- erythematous
- dysphagia
- dysphonia
- recurrent
- tonsillectomy - rate of mortality because of internal carotid artery
3
Q
what is quincy?
A
- complication of tonsillitis
- tonsillar abscess
- can be drained - beware the internal carotid artery
4
Q
what is epiglottitis?
A
cant swallow own spit and start drooling
5
Q
what are the range of lower respiratory tract infections?
A
- acute bronchitis
- acute exacerbation of chronic bronchitis
- pneumonia
- influenza
6
Q
what is the common cold?
A
- 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
7
Q
what is acute sinusitis?
A
- preceded by a common cold
- purulent nasal discharge
- resolves in 10 days
- treatment is mostly viral aetiology but sometimes antibiotics
8
Q
what is diphtheria?
A
- life threatening due to toxin production
- characteristic pseudo-membrane
- 1-10 days
9
Q
what is acute bronchitis?
A
- preceded by common cold
- clinical features: productive cough, fever, normal chest exam, normal chest xray, transient (short duration) wheeze
- antibiotics are not indicated
10
Q
what is acute exacerbation of COPD?
A
- 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
11
Q
how to manage acute exacerbation of COPD?
A
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
12
Q
what is the management of community acquired pneumonia?
A
- antibiotics: amoxicillin, deoxycycline
- oxygen: maintain SaO2 94-98% or 88-92%
- fluids
- bed rest
- no smoking
13
Q
what is mycoplasma pneumonia?
A
- no cell wall so resistant to beta-lactam antibiotics
- causes protracted paroxysmal cough eg cilial dysfunction
- h2O2 production damages respiratory membranes
14
Q
what is aspiration pneumoia?
A
need anaerobic cover
15
Q
what is legionalla?
A
- chest symptoms may be minimal
- GI disturbance is common
- confusion common
16
Q
what is primary influenzal pneumonia?
A
- seen most during pandemic years
- in young adults
- high mortality
17
Q
what is secondary bacterial pneumonia?
A
- common in infants, elderly, debilitated, pre-existing disease and pregnant women
- ## cause of mortality
18
Q
what antivirals are used in flu?
A
- oseltsmivir
- zanamivir
19
Q
what is chlamydia trachomatis?
A
- an STI which can cause infantile pneumoina
- diagnosed by CPR on urine of mother or pernasal/ throat swabs of child
20
Q
what is chlamydophilia pneumoniae?
A
- person to person
- mostly mild resp infections
- may be picked up by test for psittacosis
21
Q
what are the main routes of transmission?
A
- contact
- airborne
- droplets
22
Q
how to control droplet transmission?
A
- these are large particles > 5 micron, fall to the floor within 2m
- wash hands, PPE, keep door closed,
23
Q
what are the gram positive upper respiraotry tract colonisers?
A
- a-haemolytic streopococci inc strep pneumoinae
- b-haemyolytic streoptococci = strep pyogens
- strapholococcus areus
24
Q
what are the gram negative upper respiraatory tract coloniers?
A
- haemoophilus influenzae
- morexella catarrhalis
25
what are the aspects of acute bronchitis?
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
26
what is the microbiology of COPD?
- 30% viral alone, 50% bacterial, 20% ?
| - Haemophilus influenzae & Moraxella catarrhalis, Streptococcus pneumoniae, Gram-negatives & others
27
what are the lung defences?
- normally sterile = no ciliary escalator, alveolar lining fluid, surfacant, Ig complement, FFA, AMP
- alveolar macrophages and neutrophils
28
what is typical pneumoina caused by? (community)
streptococcus pneumoniae
29
what is atypical pneumonia caused by? (community)
- mycoplasma pneumoinae, legionella pneumoina, chlamydophila pneumonia, chlamydia psitacci viruses etc
30
what is hospital acquired pneumonia?
- if you are in hospital for more than 3 days
| - including ventilator associated pneumonia
31
what are the clinical aspects of community acquired pneumoina?
```
Cough
Increased sputum
Chest pain
Dyspnoea
Fever
CXR with infiltrates
Acquired in the community
```
32
what is the pathology of community acquired pneumonia?
Organism reaches lungs > immune activation & infiltration (systemic response) > fluid & cellular build up in alveoli leads impaired gas exchange
33
what is the microbiology of community acquired pneumonia?
```
Causative organisms:
Streptococcus pneumoniae = 70%
Atypicals/viruses = 20%
Haemophilus influenzae = 5%
Staphylococcus aureus = 4%
Other bacteria . = 1%
```
34
what happens when strep pneumonia is in the lab?
becomes partially haemolysied = green/brown colour
35
what are the infections that may be caused by strep pneumonia?
- sinus infection
- ear infection
- invasive pneumococcal disease
- meningitis
- bloodstream infection
36
what is the capsule of strep. pneumonia used for?
- it is a key virulence factor
- anti-phagocytic
- basis for vaccination
- rough strains (avirulent)
37
how do you detect legionalla?
- viral PCR
| - not sputum culture
38
what are the treatments of legionella pneumonia?
- clarythromycin, erythromycin,
| - quinolones eg levofloxacin
39
do you give amoxicillin for walking pneumonia?
no, as the organism has no cell wall
40
what are the symptoms of walking pneumonia?
- healthy young person otherwise
| rash - dark circle
41
what are the clinical aspects of whooping cough?
- 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
42
what is the microbiology of pertussis (whooping cough)?
- bordetella pertussis
- gram negative coccobacillus
- exclusively human pathogen
- vaccine preventable
