L16-InFLUenza Flashcards
What does the ‘H’ stand for on the influenza virus? What is its function?
Hema-G-Glutin-In…it Grabs on to the host cell
What does the ‘N’ stand for in the influenza virus? What it its function?
Neur-Amin-id-ase…it releases the virus into the host cell
What are two factors that lead to a high mutation rate in influenza?
ssRNA and Segmented genome
Where does influenza retrovirus replicate?
in the Nucleus! (only flu and RetroViruses do this)
What leads to a DRIFT mutation?
Just a change in one of the spikes (H or N)
What leads to a SHIFT mutation?
Segmented Genome…2 viruses 1 cell. They mix and make a new virus!
1.What is a “TYPE” of virus? 2.Which “type” is a shift mutation? 3.Which “types” cause significant human disease?
1.A “TYPE”=an influenza virus Strain!! 2.Shift mutation=Type A….3.both types A and B cause human disease
When was the “GREAT pandemic”? How many people died?
1918-1919…50-100 MILLION people died (about 1/3 of the current US population!)
Does influenza virus need to 1.code for a nucleic acid polmerase? 2.bring its own polymerase?
YES and 2.YES (-)ssRNA needs to first be converted to (+)ssRNA.
What family is influenza virus?
Ortho-my-xo-viridae
How are the subtypes of type A determined?
Hemagglutinin and Neuraminidase
Is influenzavirus enveloped or non-enveloped?
Enveloped
Which strain type causes PANDEMICS?! How often do these typically occur?
Type A…once per 20years
What “demic” is associated with drift mutation? What “demic” is associated with a shift mutation?
Drift=Epidemic….Shift=Pandemic
Where does influenza virus replicate in the human body?
Respiratory epithelium
What is one Exclusionary symptom that separates a flu from a cold?
Flu=No stuffy nose!
How many endemic (small/local) deaths occur each year?
35,000! that aint no jive turkey!
What are the reservoirs for influenza?
Humans, Birds, and Pigs
What time of year is most susceptible to influenza infections? Why?
Winter! The ENVELOPE is stronger in cold weather AND the sun promotes optimal human immune response (VitD)
What type of vaccine is the most common influenza vaccine?
A trivalent vaccine (eg. H1N1, H3N2, B)
Which age group does the vaccine have the LEAST amount of effectiveness?
only 30-40% effective among frail/elderly persons (THE MAIN TARGET GROUP!)
