Influenza (Flu) Flashcards
flu
a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and sometimes the lungs.
It can cause mild to severe illness, and at times can lead to death. The best way to prevent flu is by getting a flu vaccine each year
Signs and Symptoms
a. fever
b. muscle ache
c. headache
d. sore throat
e. nasal congestion
f. dry cough
g. fatigue
Causative Agent
influenza A virus
N flu one za
Pathogenesis
1-attaches to specific receptors on ciliated epithelial cells and allows viral entry=Hemagglutinin antigen (HA)
2-Aids in release of newly formed virions =Neuraminidase antigen (NA)
Aids in release of newly formed virions
vi re yan
vi rion
Neuraminidase antigen (NA)
noo ra min id aiz
neur amin i dase
(1) attaches to specific receptors on ciliated epithelial cells
(2) allows viral entry ?
Hemagglutinin antigen (HA)
he moh glitn nin
hem agg lutin
Prevention:
vaccine (developed annually since virus changes so quickly)
aan u lee
ann ually
treatment
antivirals
immunity hampered by:
1-antigenic drift
2-antigenic shift
Epidemiology
inhalation
immunity hampered
ham pird
ham per ed
antigenic shift
- more dramatic change
- uncommon
- cause of pandemic influenze
- two different viruses infect same cell at same time
antigenic drift
ga nic drif it
dri ft
responsible for yearly occurrence known as seasonal influenza
minor mutations in genes that code for HA & NA Ags leads to gradual change
