1. Paramyxoviruses_Flashcards
What is the genetic material and structure of Paramyxoviruses?
Linear single-stranded RNA (ssRNA), helical, enveloped.
How do Paramyxoviruses replicate?
Contains RNA polymerases (L and P proteins), allowing cytoplasmic replication.
What protein allows Paramyxoviruses to fuse with host membranes?
Fusion (F) protein.
How are Paramyxoviruses transmitted?
Via respiratory droplets, highly contagious during the incubation period.
What unique cytoplasmic and nuclear characteristic do measles have?
Measles has both nuclear and cytoplasmic inclusion bodies.
Which Paramyxoviruses contain both HA and NA proteins?
Parainfluenza and Mumps.
Which virus contains only HA?
Measles.
Which virus lacks HA and NA proteins?
Respiratory Syncytial Virus (RSV).
What is the incubation period of Parainfluenza virus?
2–6 days.
What environmental factors inactivate Parainfluenza virus?
Easily inactivated by dryness or acid.
Which epithelial cells does Parainfluenza target, and how does it affect immunity?
Targets ciliated epithelium of the upper respiratory tract, reducing IgA production.
What are the clinical features of Parainfluenza Type 1 and 2?
Mild upper respiratory tract infections (URTI), including croup (laryngotracheobronchitis).
What are the clinical features of Parainfluenza Type 3?
Can cause viral pneumonia and epiglottitis, especially in children.
What is the most common viral cause of pneumonia, and what is the second?
1st: RSV, 2nd: Parainfluenza.
How is Parainfluenza diagnosed?
Nasal secretions and throat swabs, cultured in monkey kidney cells (CPE).
