Viral respiratory infections Flashcards
Upper respiratory pathogens replicate best at what temperature?
33-35 C
How can damage predispose patients to bacterial super-infections?
- Interruption of mucociliary escalator2. Weaken immune system
What are symptoms of the common cold?
- Rhinitis2. Pharyngitis3. NO high fever, LRT involvement, or respiratory distress
What is the peak seasonal incidence for the common cold?
Spring and Fall
What is the virology of rhinoviruses?
- Picornavirus2. Non-enveloped3. +ssRNA4. Three types - A, B, C
Rhinoviruses are part of what family of viruses?
Picornavirus
Are rhinoviruses enveloped or non-enveloped?
Non-enveloped
What is the genome for rhinoviruses?
+ssRNA
How are rhinoviruses transmitted?
- Direct contact with nasal secretions2. Large droplets 3. Contaminated fomites
What is the incubation period for rhinoviruses?
1-3 days
What is the pathogenesis of rhinoviruses?
- Infect ciliated mucosal epithelial cells 2. Virus enters cell, starts replicating, causes tissue damage3. Epithelial layer damage leads to vascular permeability and outpouring from lamina propria
What is the virology of non-SARS coronaviruses?
- Enveloped - glycoprotein coat 2. +ssRNA
What is the incubation period for coronaviruses?
3 days
Where do non-SARS coronaviruses replicate?
Epithelial cells of respiratory tract
Is there a vaccine for non-SARS coronaviruses?
No
What is the virology of adenoviruses?
- Non-enveloped2. dsDNA genome3. Adenoviral fiber is toxic protein virulent factor 4. No seasonal pattern of illness
What adenovirus serotypes cause respiratory disease?
1, 2, 5
What are the transmission routes for adenoviruses?
- Oral2. Droplet inhalation 3. Conjunctiva
Where do adenoviruses replicate?
Epithelial cells, cause damage there
Are adenoviruses enveloped or non-enveloped?
Non-enveloped
What is the adenovirus genome?
dsDNA
What is the adenovirus virulent factor?
Adenoviral fiber - toxic protein
How long can patients shed adenovirus virions following infection (without clinically apparent disease)?
6-18 months
Is there a seasonal pattern of illness for adenovirus?
No
What is pharyngoconjunctival fever?
- Caused by adenovirus 2. Conjunctivitis3. Phayngitis
What do adenovirus serotypes 40 and 41 cause?
Gastrointestinal disease
What other illnesses can adenoviruses cause?
- Pharyngoconjunctival fever2. Croup 3. Bronchiolitis4. Pneumonia
What is the virology of coxsackieviruses?
- Enterovirus subfamily of picornaviruses2. Non-enveloped 3. +ssRNA 4. Replication in cytoplasm 5. Can survive low pH of GI tract
What type of virus is coxsackievirus?
Enterovirus subfamily of picornaviruses
Is coxsackievirus enveloped or non-enveloped?
Non-enveloped
What is the coxsackievirus genome?
+ssRNA
Where does coxsackievirus replicate?
Cytoplasm
What is the most common virus responsible for herpangina?
Coxsackievirus (type A)
How is coxsackievirus transmitted?
Fecal-oral