42 Influenza Flashcards
Influenza viruses of veterinary importance are all Influenza __ (letter) viruses.
Influenza A
What kind of genome does influenza have?
Single stranded, negative sense RNA
Influenza viruses are/are not enveloped
Enveloped
What is the function of hemagglutinin (HA)?
Binds a-2,3 or a-2,6 sialic acid receptors on epithelial cells
What is the function of neuraminidase?
Allows release of the new viruses from the host cell by cleaving the sialic acid via hydrolysis.
Describe antigenic shift.
During a co-infection, as the virus is assembling it picks up some genetic material from both viruses. Changes the sybtype.
Describe antigenic drift.
SNPs/RNA mutations in the virus, changing the sequence but not the subtype. No co-infection required.
T or F: avian influenza (NOT HPAI) usually causes severe disease in wild birds.
F; rarely cause disease
Where do avian-adapted viruses bind?
a-2,3 sialic acid receptors in the gut
Where do mammalian adapted viruses bind?
a-2,6 sialic acid receptors in the resp tract.
Pandemic influenza is caused by antigenic ___ (shift/drift)
Shift
Seasonal influenza is caused by antigenic _____ (shift/drift)
Drift
How is zoonotic influenza transmitted?
Animals to humans with no sustained human-to-human transmission
What is required for an influenza pandemic?
-New (novel H/N combination) influenza virus that has not recently circulated/has never circulated in people before
-New virus infects people and causes disease
-Virus is easily transmitted from person to person
What is the reservoir of all Influenza A’s?
Birds
