Respiratory syncytial virus

Question 1

type

Answer 1

Paramyxoviridae
Enveloped
Helical
Linear ss(-)sense
RNA
Replicate in
cytoplasm

Question 2

Transmission
& season

Answer 2

Leadings
cause of LRTI
in infants and
young children
Fall & Winter:
Except:
* Florida:
July-March *
Tropic: rainy
season
Risk factors: -
infants<6
months
-infants &children with
underlying lung
disease
- premature
birth(<35
weeks)
Congenital
heart disease
- passive
smoking
- down
syndrome
Entry via
epithelia of
nose and eye

Question 3

presentation

Answer 3

Bronchiolitis: inflammation of
the bronchioles and small
bronchi
<2 years of age, fall and winter
URI sx followed by LRT
infection with inflammation →
wheezing or crackles (attacks
terminal bronchioles)
Viral pneumonia

Question 4

Pathogenesis

Answer 4

1. Fusion factor(peplomer):
   main viral antigen- membrane
   fusion
2. G glycoprotein: involved in
   attachment & entry, also
   interferes with interferon
   production
3. Lacks glycoprotein with HN
   activity
   Primary site of
   replication=nasopharyngeal
   epithelium
   Direct cytopathic effect→ loss of
   function (impair ciliary function)