Influenza Flashcards
what are the general symptoms of the flu
malaise, cough, fever, rhinitis, muscle pain - the shit you should know cause youre a nurse :)
whats the incubation time for the flu?
1-4 days & symptoms resolve usually in one week
what are 2ndary complications?
bacterial infections that come with the flu from decreased immunity and exposure! - kills a shit ton of people each year (39,000)
transmission of the flu is only _______ to _______
human to human
how long is someone contagious with the flu?
1 day before CM’s present and 1 week after symtpoms manifest
1918 spanish flu.. talk about it
most deadly flu in all of history - killed more people that the world war did
Why did the 1918 spanish flu affect more young people?????? **
CYTOKINE STORM- the immune system overreacted in such a dramatic way and he immune system started to damage the body = = multiple organ failure
** healthy immune system was more of a liability then an asset
what does the influenza virus contain?
contains RNA virus- with 8 RNA segments and it NEGATIVE (ssrna)
what is the influenza virus surrounded by?
pieomorphic envelope that is studded with prominent glycoprotien spikes composed of:
hemagglutinin (HA) and neuraminidase (NA)
how do we use NA and HA against the virus?
the antibodies (anti HA and anti NA) - binds to NA active center - blocking the binding to sialic acid - mutations - death
the flu virus gets new mutations every year - this is bad because???
the genetic changes to the virus ensure that the adaptive immune system cant respond to it (because its brand new) - so there is no protection!
name the three types of influenzas and who they affect
type a: humans and animals!!!!!
type b: humans only
type c: who the fuck knows
What the main difference between antigenic shift and antigenic drift?
SHIFT: complete mutation and 100% change
DRIFT: gradual change
why does antigenic drift happen? & what is the result of this?
because the RNA dependent and the RNA polymerase is not linked to proof reading mechanisms so there is a high mutation rate -
MUTATION IN THE GENOME
so… the immune system can not fully protect us every year with the flu since it changed so much
what types of flu does antigenic shift happen in?
type A
what types of flu does antigenic drift happen in?
all
Why does antigenic shift happen ? and what is the result of this?
the subtypes (NA and HA) complete change all together (reassortment of genome) result of this: no antibodies at all = no immunity whatsover = no protection
Whats the most dangerous type of flu?
type A
Type A has 3 things mechanisms that make it the most dangerous and at risk for antigenic shifts, what are they
they have:
- animal reservoir
- antigenic shift
- human pandemics
Swine flu is considered classic reassortment, why?
cause it contains a unique combination of gene segments from four different sources:
– swine, avian bird flu, human, 2nd swine.
Theory behind antigenic shift is…
reassortment of HA & NA genes between human and avian influenza virus in a 3rd host (a fucking piggy wiggly woo)
Differences between h5n1 and seasonal flu
h5n1: spreads slowly and often fatal – found in the lower respiratory tract and can lead to pneumonia and death
seasonal flu: spreads early and rarely fatal - found in the upper respiratory track so secretes alot- spreads!
Explain absorption, assembly and release of the influenza virus
Absorption: virus HA on the virus particle attached to sialic acid on the cell surface
•HA is an attachment proteins - The HA spikes bind to sialic acid, the receptor for the influenza virus
Assembly: virus HA sticks new virus particles to sialic acid on cell surface and to other virus particles
—-Mediated when virus makes a lot of genetic material that is packaged together membranes (HA and NA- )
Release: NA removes sialic acid from cell surface and virus, severing the connection between the virus and cell; thereby releasing viruses
How does tamiflu work against the flu virus?
since the flu virus requires NA to escape from the cell by removing siliac acid - tamiflu binds to NA’s active center and inhibiting it
