Respiratory tract infections (excluding pneumonia, flu and TB) Flashcards
Name upper respiratory tract infectious conditions
Common cold (coryza)
Sore throat (pharyngitis)
Sinusitis
Epiglottitis
What is coryza?
Acute viral infection of the nasal passages
What are the clinical features of coryza?
A self-limiting nasal discharge (becoming mucopurulent over a few days)
Often accompanied by a sore throat
Sometimes accompanied by a fever
How is coryza spread?
By droplets and fomites
Fomites = any form of transmission of a virus or bacteria
Name some complications of coryza
Sinusitis Acute bronchitis Otitis media Pneumonia Febrile convulsions
What is the main cause of corzya?
Rhinoviruses
Why is there more chance of getting coryza at lower temperatures?
Because rhinoviruses proliferate best at 32 degrees centigrade.
What is acute sinusitis?
Infection of the sinuses
How do you distinguish between sinusitis and a common cold?
Pain in the sinuses
What are the clinical features of sinusitis?
Pain in the sinuses
Preceded by a common cold (coryza)
Purulent nasal discharge
What is the treatment of sinusitis?
Give antibiotics if it is persistent over a week.
a) What is tonsillitis?
b) How is it treated?
a) Inflammation of the tonsils. When enlarged, they are painful and can obstruct the airway.
b) Antibiotics
a) What is quinsy?
b) How is it treated?
a) Paratonsilar abscess
b) Incision and drainage
a) What is diptheria?
b) What causes it?
a) An acute inflammation which most frequently affects the fauces, soft palate and tonsils.
b) Corynebacterium diptheriae
Is diptheria still seen in the UK?
No- due to vaccination
How can diptheria be life-threatening?
Due to its toxin production.
The toxin webs across the throat, causes sepsis and death.
What often causes acute epiglottitis?
Haemophilus influenzae
Why is tracheostomy preferential to intubation in a child with epiglottitis?
Attempt at intubation often causes more swelling of the epiglottis, hence more airway obstruction. Could cause death.
What is acute bronchitis?
The cold which goes into the chest:
Preceded by a common cold. Either the virus or the inflammation (inflammatory cells) move down the airway.
(Unless the patient has an underlying chronic lung disease in which case a secondary bacterial infection is more likely to be the cause).
What are the clinical features of acute bronchitis?
Productive cough A fever in a minority of cases Normal chest examination Normal CXR May have a transient wheeze
Are antibiotics indicated for acute bronchitis?
Not unless the patient has an underlying chronic lung disease.
What are the clinical features of an acute exacerbation of chronic bronchitis?
Usually preceded by an upper respiratory tract infection.
There is worsening of sputum production which is now purulent.
More wheezy.
Breathless.
On examination:
Breathless, wheeze, coarse crackles, may be cyanosed, ankle oedema in advanced disease.
Describe the management of an acute exacerbation of chronic bronchitis.
Antibiotics: amoxicillin or doxycyclin
Bronchodilator inhalers
Short course of steroids in some cases
Refer to hospital if:
Evidence of respiratory failure or not coping at home.
In hospital:
Same as before plus ABGs, CXR, oxygen if respiratory failure
Name the lower respiratory tract infections
Acute bronchitis
Acute exacerbation of chronic bronchitis
Pneumonia
Influenza
Which group of patients is commonly affected by bronchiolitis, especially in the Winter months?
Young children, particularly those aged 1/2.
How does bronchiolitis present?
Young children (1 or 2) Fever Coryza Cough Wheeze Severe cases: Decreased Pa02, grunting, intercostal/sternal indrawing.
Which pathogen causes most cases of bronchiolitis?
Respiratory Syncytial virus
Name complications of bronchiolitis, and describe the patients in whom these complications would be seen.
Complications: Respiratory failure, Cardiac failure
Patients: Premature, or with pre-existing respiratory or cardiac disease.
How is RSV confirmed in the lab?
By PCR on throat or pernasal swabs
What is the therapy for RSV?
Supportive
What is cohort nursing and why is it used in treating patients with bronchiolitis?
Cohort nursing: all the children with bronchiolitis are in the same ward and the nurses dont care for other children with different diseases.
This is because nosocomial spread is common.
What is another virus that causes RSV-like symptoms in adults and children?
Metapneumovirus
How are samples taken for PCR?
Throat swabs in viral transport medium, broncheoalveolar lavage, endotracheal aspirate.
Which viruses are currently tested for in Tayside?
Flu A , Flu B, Adenovirus, Rhinovirus, RSV, Metapneumovirus, Parainfluenza virus 1-4
What is chlamydia trachomatis?
An STI
Can cause infantile pneumonia
How is chlamydia trachomatis detected?
PCR on urine of mother or pernasal/throat swabs of infant.
What does chlamydophila pneumoniae cause?
Mild respiratory infections.
a) What does MERS coV stand for?
b) What countries have affected patients picked it up from?
a) Middle East Respiratory Syndrome coronavirus
b) Jordan, Qatar, Saudi Arabia
What are infections of the trachea and bronchi?
Acute epiglottitis
Acute exacerbations of COPD
Cystic fibrosis
Pertussis (whooping cough)
Which pathogen causes acute epliglottitis?
Haemophilus influenzae
Where does haemophilus influenzae live?
The upper respiratory tract
What type of bacteria is haemophilus influenzae?
Small gram negative bacillus
What does haemophilus influenzae culture look like on chocolate agar?
small translucent colonies
How can Haemophilus influenzae be identified?
From the X and V test:
Haemophilus influenzae requires both X and V to grow
How is acute epiglottitis diagnosed?
Blood culture
How is acute epiglottitis treated?
With ceftriaxone
What is an acute exacerbation of COPD?
It often follows a viral infection or a drop in temperature with increase in humidity (often in Winter)
30% are viral and 30 - 50% are bacterial in origin. The cause of the remainder is unknown.
Patients present with increased breathlessness and increased volume and purulence of sputum.
What are the most common bacterial organisms associated with acute exacerbations of COPD?
What do all of these pathogens have in common?
Haemophilus infleunzae
Streptococcus pneumoniae
Moraxella Catarrhalis
They are all part of the normal Upper respiratory tract flora.
Describe the treatment for an acute exacerbation of COPD.
Antibiotics: Give antibiotics if there is an increase in sputum purulence. If there is no sputum purulence, antibiotics are not required unless there is consolidation on the CXR or other signs of pneumonia.
1st line: Amoxilcillin 500mg 3x daily ( 5 days)
2nd line: Doxycycline 200mg on day 1 then 100mg for 4 days
Why do acute exacerbations of COPD become increasingly difficult to treat with time?
Due to the acquisition of more resistant organisms.
What is the problem in cystic fibrosis?
It leads to abnormally viscid mucous which blocks tubular structures in many different structures including the lungs.
Chronic respiratory infection is a major problem.
What are common causal bacteria in respiratory infection in CF?
Staphylococcus aureus and haemophilus influenzae
Psuedominas auruginosa
Burkholderia cepacia
Which pathogen causes pertussis?
Bordetella pertussis
How is pertussis diagnosed?
Pernasal swab
Serology
Clinically - by the time of paroxysmal coughing, the organism numbers are much reduced
When is treatment of pertussis most effective?
What other measures are in place to reduce prevalence of pertussis?
In the first 10 days.
Vaccination.
Name some infections of the lungs
Community acquired pneumonia Nosocomial pneumonia Legionnaires disease Pneumocystitis carinii pneumonia Fungal chest infection Tuberculosis
What is Legionnaires disease?
What is it associated with?
A flu like illness which may progress to a severe pneumonia, with mental confusion, acute renal failure and GI symptoms.
It is often associated with travel and usually associated with water.
How is legionnaires disease diagnosed?
Legionnella urinary antigen and serology
For culture, a special culture is required and is slow growing.
PCR test on sputum
What is the treatment of Legionnaries disease?
Erythromycin/ clarythromycin
Fluoroquinolones e.g. levofloxacin
a) Name a cause of pneumonia in patients with AIDS.
b) How is it diagnosed?
c) How is it treated?
a) Pneumocystitis carinii pneumonia
b) Bronchioalveolar lavage or induced sputum and identification of cysts
c) Cotrimoxazole, pentamidine
a) Name a cause of a fungal chest infection
b) What diseases can it cause?
c) How is it diagnosed?
d) How is it treated?
a) Aspergillus fumigatus
b) Severe pneumonia or systemic infection in the severly immunocomprimised
Or aspergilloma
c) Culture
d) IV Amphotereicin B
Describe some ways of diagnosing lung infections
- Isolation of the causal pathogen: Sputum, Blood culture (the organism is in the blood of 1/3 patients with pnuemonia)
- Detection of bacterial antigen: e.g. legionnella urinary antigen, direct immunofluorescence for PCP
- Serology : legionnella serology
What forms of respiratory spread are there?
Droplet spread: Large particles >5 microns, travel 1-3 feet
Airborne transmission of infectious droplet nuclei: particles < 5 microns, travel 5- 160+ feet
When does droplet spread occur?
Coughs and sneezes
