Viral infections of the resp system Flashcards
List the viruses associated with resp system conditions (6)
Rhino virus,
Enteroviruses,
Parainfluenza virus,
Respiratory Syncytial Virus, Human Metapneumovirus, Adenoviruses
list the common respiratory conditions (11)
Rhinitis, sinusitis, otitis media, tonsilitis, pharyngitis, tracheitis, bronchitis, bronchiolitis, laryngo-tracheo-bronchitis (croup), bronchopneumonia, pneumonia
Common old is limited to the LRT (t/f)
False. it is limited to the URT
Incubation period of the common cold
1 to 3 days
List the prodromal (early) symptoms of the common cold
headache, sore throat, fullness in the nose.
describe the mucus changes in the common cold as the condition progresses.
Profuse watery discharge from the nose (rhinorrhea) becomes thicker, muco-purulent and decreases
in volume
How long does a common cold take to resolve
About a week
List the viruses responsible for the common cold
Rhinoviruses: approximately 100 serotypes account for approximately 50% of colds
* Coronaviruses: NOT the serious coronaviruses
* Other enteroviruses
* RSV/Para-influenza/Influenza
Pharyngitis/tonsilitis is mostly caused by what microorganism species? which one is the most common culprit?
70% mostly viral
Mostly by adenovirus
In pharyngitis/tonsilitis, some viruses can cause _______________ which can progress to form ___________________
vesicles(blisters»»»> ulcers
Why is it called laryngotracheobronchitis in children?
In children difficult to distinguish due to very close anatomy, so sometimes called laryngotracheobronchitis
Laryngitis causes_______________________
Tracheitis causes______________
- Hoarse voice
- Sore throat and cough
Laryngotracheobronchitis can present as croup with stridor in children. What is that?
a particular high pitched sound with inspiration and sometimes
even on expiration – due to narrowed airway
T/F acute bronchitis is mostly caused by viruses
T
describe chronic bronchitis
not infective
* Due to irritation typically from smoking, but also from pollution, fumes, inhaled dust
What causes acute exacerbations of chronic bronchitis and how are they treated?
Acute exacerbations may be precipitated by infections though probably mostly these are viral. In practice often treated with antibiotics, but it is an area of uncertainty
what accounts for accounts for 30 -50% of community acquired pneumonia?
viral pneumonia
In pneumonia, how does the virus reach the lungs?
Mainly reach lungs via respiratory tract,
* Attach to respiratory epithelium by surface molecules that adhere to ‘receptors’
Healthy people are not at risk of viral pneumonia. T/F? Explain
Healthy people also susceptible
* But severity varies according to age and immune status, including prior exposure to virus
Possible complications of viral pneumonia
Can predispose to secondary bacterial infection, e.g. influenza can be followed by pneumococcal or
staphylococcal infection
* Permanent lung damage, e.g. bronchiectasis after certain destructive viral infections
What determines the site of infection for a particular virus?
Some viruses may have predilection or preference for certain sites
Sometimes depends on age and anatomy
Immune status ( age, previous infections or vaccinations, presence of immunodeficiency)
Why does the rhinovirus tend to infect the nose?
they prefer slightly cooler temperatures for replication
infants and young children more prone to clinical features of croup. Why?
because of narrow subglottic airway so swelling more easily leads to obstruction
Why are children more likely to develop otitis media?
Eustachian tube between nasopharynx and middle ear is more open in this age group so
also more likely to develop otitis media