Respiratory infections Flashcards
What is coryza? viral or bacterial? spread by? what organisms?
Common cold:mild fever/sore throat
- viral infection nasal passages: adenovirus, rhinovirus, RSV
- spread by droplets and formites
What is acute sinusitis usually preceded by? what does it cause? viral or bacteral? treatment?
- Preceded by a common cold
- purulent nasal discharge
- viral aetiology
- self limiting: 10 days
What is diptheria? caused by? what is characteristic? other clinical features?
- infection caused by bacterium Corynebacterium diphtheriae.
- Signs and symptoms may vary from mild to severe
- life threatening due to toxin production
- characteristic ‘pseudomembrane’
- sore throat/fever/barking cough/swollen neck due to lymph nodes
- vaccination in UK
Acute bronchitis:
- preceded by?
- clinical features?
- treatment?
- preceded by common cold
- productive cough, minority have fever, may have transient wheeze
- supportive tx
What are the clinical features (5) of an acute exacerbation of COPD? What clinical signs are seen?(5)
Usually preceded by upper respiratory tract infection
Increased sputum production
Increased sputum purulence
More wheezy
Breathless
OE: Respiratory Distress Wheeze Coarse crackles May be cyanosed In advanced disease – ankle oedema
What is the management for an acute exacerbation of COPD? when to admit?
- Antibiotic: 1st line amox. 500mg TDS for 5 days, 2nd line Doxy. 200mg OD for 1st day and then 100mg OD for further 4 days
- Bronchodilator inhalers
- Short course of steroids in some cases
Admit if:
- evidence resp. failure
- not coping at home
What is the CURB65 severity score?
C New onset of confusion U Urea >7 R Respiratory rate >30/min B Blood pressure Systolic <90 OR Diastolic <61 65 age 65 years or older
Score 1 for each
What is the treatment for community acquired pneumonia?
CURB65:
0-2: amox. 1g TDS IV/PO 5days or doxy 200mg day 1 then 100mg OD (IV clarith. if NBM)
3-5 (severe): Co-amox IV 1.2mg TDS + doxy. 100mg PO BD
if in ICU:
Co-amoxiclav IV 1.2g tds + Clarithromycin IV 500mg bd
Severe - If penicillin allergic: IV Levofloxacin 500mg bd
Step down to Doxycycline 100mg bd for all
patients with severe CAP
What are 3 clinical complications of pneumonia?
- respiratory failure
- pleural effusion
- empyema
What are the aetiology for:
Classical flu
Flu-like illnesses
Bacterial cause - is this a primary cause for flu?
Classical:
- influenza A
- influenza B
Flu-like:
- parainfluenza
- many others
Haemophilus influenza:
-not a primary cause of flue but may be a secondary invader
What is the transmission of flu?
Droplets/resp. secretions
What are the four complications of flu?
Primary influenzal pneumonia:
- seen most during pandemic years
- can be disease of young adults
- high mortality
Secondary bacterial pneumonia:
-more common in infants/elderly disabled/pre-existing disease/pregnant women
bronchitis
otitis media
What is influenza infection during pregnancy assoc. with? (4)
- perinatal mortality
- prematurity
- smaller neonatal size
- lower birth weight
Flu treatment
supportive, paracetamol, fluid, bed rest
How can you detect influenza virus?
PCR:
-nasopharyngeal swabs in virus transport medium
Antibody detection:
- other hospitals
- often retrospective
- may need paired acute and convalescent bloods
What are the main differences between the killed flu vaccine and the live attenuated vaccine:
- what do they contain?
- who recieves either vaccine?
- administered?
Killed vaccine
currently contains 2 different influenza A viruses and one influenza B virus
given annually to adult patients at risk of complications
given to health care workers
Given to children aged 6 months to 2 years at risk of complications
Live attenuated vaccine
Also contains 3 viruses
More effective than killed vaccine in children aged 2-17
Offered this year to ALL children aged 2-5, and all primary school children
Administered intra-nasally
How effective is flu vaccine?
no more than 70% effective at preventing clinical disease
Are antivirals ever used after a contact with flu?
-rare
What are the usual bacterial organisms found for:
- mild/moderate pneumonia
- severe pneumonia
What is important to remember for pneumonia post flu?
Mild/moderate:
- strep. pneumoniae
- haemophilus influenzae
- staph. aureus
Severe pneumonia:
as above but possible coliforms and atypicals such as:
m. catarrhalis, Mycoplasma pneumoniae, Legionella pneumophilia, Chlamydophila pneumoniae & Chlamydophila psittaci
Remember Staph aureus
pneumonia post influenza and the PVL producing strains of Staph aureus that can produce severe pneumonia in children and young adults especially
What bacterial organisms can be seen in hospital acquired pneumonia?
-strep. pneumoniae,
Haemophilus influenzae
and coliforms.
Legionella can be hospital acquired.
What coliforms can cause pneumonia? what are the risk factors for this?
Klebsiella
Escherichia coli
Enterobacter
Proteus
Pseudomonas aeruginosa
- debilitated
- chronically ill
- alcoholism
What type of pneumonia is seen in those with immune defects and anatomical abnormalities (4)
Opportunistic pathogens
-Fungal pneumonia: Candida spp. causing candidiasis.
Aspergillus spp. causing aspergillosis.
Mucor spp. causing mucormycosis.
Cryptococcus neoformans causing cryptococcosis.
recurrent pneumonia
Pneumocystis jiroveci pneumonia (PJP), formerly known as Pneumocystis carinii pneumonia (PCP) - one of the most frequent and severe opportunistic infections in people with weakened immune systems.
Protozoa:
cryptosporidia, toxoplasma
Virus:
cytomegalovirus - CMV
Opportunistic bacteria (as well as virulent infection with common organism e.g. TB): Mycobacterium avium intracellulare
How can you diagnose community acquire pneumonia?
Sputum culture - purulence/viral PCR
Which viruses can cause community acquire pneumonia?
Flu A/B Rhinovirus RSV Human metapneumovirus (hMPV) Parainfluenza 1-4 Adenovirus Coronaviru
Describe the clinical features of legionella pneumonia
Flu like illness which may progress to a severe pneumonia, with mental confusion, acute renal failure and GI symptoms.
Mortality 5-30%
How is legionella spread?
water droplets
What are the risk factors for legionella (2)?
- exposure of contaminated aerosolised water
- impaired immunity: >55yo, diabetes, smoking, malignancy, altered immunity
How is legionella pneumonia diagnosed?
-Legionella urinary antigen
Detects serogroup 1 only
-Culture
Slow on selective media
-Paired serology
Rise in titres
Now PCR available direct from Sputum
What is the antibiotic treatment for legionella pneumonia?
- clarythromycin, erythromycin
- quinolones (e.g. levofloxacin)
What is the treatment for severe vs non-severe aspiration pneumonia?
Severe:
-IV amox + met + gent
(if penicillin allergic change amox to co-trimoxazole)
step down to:
PO co-trim. + metronidazole (total IV/PO 7 days)
Non-severe:
-PO amox + metronidazole 5 days
What organisms can cause exac. of COPD?
Haemophilus influenzae & Moraxella catarrhalis (gram -ve coccus), Streptococcus pneumoniae (gram +ve diplococci), Gram-negatives & others
What is the treatment for COPD exac.?
Only treat if increase in sputum purulence or new CXR changes or pneumonia
Empiric treatment as per NHST policy
1st line Amoxicillin 500 mg TDS (5 days)
2nd line Doxycycline 200mg D1 > 100 mg D2-5
Aim to cover in 1st instance H. influenzae, M. catarrhalis & S. pneumoniae
