Respiratory Viruses Flashcards
Describe bronchiolitis
- Occurs in < 2 years old
- Inflammation and plugging of small bronchioles
- Caused by RSV
- Might need oxygen/NIV
- Rare in first month of life
- Peak age 2-5 months
What are clinical presentations of respiratory viruses (depending on virus and host)?
- Bronchiolitis
- Pharyngitis
- Common cold (rhinorrhea)
- Croup
- Pneumonia (primary viral or secondary bacterial)
- Influenza-like illness
- Extra-pulmonary illness (gastroenteritis, encephalitis, myocarditis)
- MERS
How are most viruses spread?
Droplet spread (not respiratory route)
What is the incubation period of influenza?
1-4 days
What is the incubation period of RSV?
2-8 days
What is the incubation period of MERS?
< 14 days
What are the three upper respiratory tract infection syndromes?
1) Common cold
2) Pharyngitis
3) Laryngitis
What are the key features of common cold?
- Nasal obstruction
- Nasal discharge
- Sneezing
What are the key features of pharyngitis?
- Sore throat
- Inflammation
- ± exudates
What is the key feature of laryngitis?
Hoarseness
What are the three syndromes associated with infection of the major airways?
1) Croup (laryngo-tracheo-bronchitis)
2) Tracheobronchitis
3) Bronchiolitis
What are the key features of croup?
- Hoarseness
- Barking cough
- Stridor
- Associated with apnoea
What are the key features of tracheobronchitis?
- Cough
- Substernal pain
What are the key features of bronchiolitis?
- Cough
- Dyspnoea
- Wheezing
What is lower respiratory tract infection?
Pneumonia/pneumonitis
What are the key features of pneumonia/pneumonitis?
- Cough
- Dyspnoea
- Chest pain
- Rales (crackles)
What are the key features of influenza like illness?
- Upper and lower respiratory tract symptoms
- Systemic symptoms - fever, malaise, myalgia, headache, chills
What is the common cause of bronchiolitis?
RSV
What are the common causes of the common cold?
Rhinoviruses
Coronaviruses
(Parainfluenza viruses)
Enteroviruses
What is the common cause of croup?
Parainfluenza viruses
What is the common cause of influenza like illness?
Influenza viruses
What are the common causes of pneumonia?
Influenza viruses
RSV
Adenoviruses
What is R0?
The average number of individuals you will infect if you have that disease
How are influenza viruses classified?
H?N?
How is influenza transmitted?
- Coughing and sneezing causes aerosolisation
- Large droplets
- Direct contact with secretions
What are the causes of influenza deaths?
- Secondary bacterial pneumonia
- Increases risk of MIs and strokes bc immune response leads to hypercoagulability
- Viral pneumonitis
How many days before the measles rash can someone be infectious?
4 days
When is ECMO used?
When the lungs can’t ventilate
When is tamiflu/oseltamivir (antiviral) effective?
As a prophylactic agent
Why is oseltamivir not v effective once the patient is symptomatic?
- There are a huge number of respiratory tract cells infected which are going to die so stopping replication might not help very much
What can measles cause?
Pneumonitis
What happens for a year after you have measles?
You have immunoparesis where your immune system is less effective
What can CMV cause?
Multifocal patchy pneumonia
