Respiratory viruses II Flashcards
How common are viral respiratory infections?
82% of respiratory infections have a viral etiology
Which virus causes lower respiratory tract infections in infants and young children, mild URTI in adults and pneumonia in the elderly?
RSV
What three infant subgroups are at risk for serious complications following an infection with RSV?
Premature, immunocompromised, and infants with congestive heart disease
What is the risk of mortality in infants with RSV?
<1% in healthy children
30% in children with congenital heart disease
70% in children with CHD and pulmonary hypertension
What causes bronchiolitis with an RSV infection?
Necrosis of bronchiolar epithelium within 18 -24 hours –> submucosal edema, with mucosal/cellular debris causing occlusion of the bronchioles.
This leads to air trapping and hyperinflation
What is the transmission of RSV?
Respiratory
Where are samples taken for a work-up of a respiratory infection?
nasopharyngeal aspirate
What is the treatment for infants that are considered high risk for RSV?
Palivizumab is given prophylactically to high risk infants.
It is humanized Ig— effective but very expensive. Neutralizes the virus
Why must palivizumab be given prophylactically?
They antibodies are only against the prefusion form of the virus- once the virus is fused it will no longer bind palivizumab
What viral infection mimics RSV in infants?
Human Metapneumovirus
What are the most common symptoms associated with parainfluenza virus?
Infection is limited to the respiratory tract. URT infections are most common, but significant disease can occur with lower respiratory tract infection
Do parainfluenza infections cause viremia?
No
What is the syncytia pattern seen with RSV infections?
The syncytia pattern results from the amalgamation of of cells with the loss of cell borders –> multinucleated cells and intracytoplasmic inclusions
How long is the immunity generated from a natural RSV infection?
short-lived, but subsequent disease is of a lesser severity
How long is the immunity generated from a parainfluenza infection?
Short-lived
