Flashcards in Influenza Deck (77):
How does chest x-ray look with seasonal flu?
how long does acute infection of seasonal flu?
7 days, cough lasts a few weeks
at risk groups for seasonal flu?
incubation (days) of seasonal flu?
infectiousness of seasonal flu (days)??
deaths worldwide from seasonal flu?
1/4 to 1/2 MILLION
Influenza binds to what on non-ciliated respiratory epithelium?
sialic acid sugar
What kind of linkage on the sialic acid is it to galactose?
Flu spreads from infection site?
Which airways does influenza like to replicate?
what cytokine causes malaise, head and muscular aches?
What cytokine causes fever?
where is ciliated epithelium in respiratory system?
trachea and bronchi
Do you normally get viral pneumonia with flu?
Nope, usually due to secondary bacterial infections after cilia destruction
Influenza have envelopes?
Influenza and Rotavirus has what kind of genome?
single stranded -ve sense RNA
T/F?Influenza B can infect other species but only A is humans
False. B infects humans only, A infects other species
Influenza C is a major problem these days?
Naw. minor pathogen bro.
HA and NA for Influenza stands for?
What does NS1 the non-structural protein in Influenza do?
how man gene segments in Influenza? encodes how many proteins?
8 segments encode 10+ proteins
how many polymerase subunits does Influenza come packaged with per RNP?
What is RNP in Influenza?
HA is the snipper in Influenza?
Nope, the gripper
NA is the gripper or snipper in Influenza?
How many subtypes of HA and NA do we know of for Influenza?
how many subtypes of HA and NA are there for Influenza B?
What are the ancestral hosts of Influenza A?
Current Influenza A subtypes in humans are?
How is Influenza taken into the cell?
receptor mediated endocytosis
How does the 8 viral RNPs escape the vacuole once in the cell?
increase acid, HA changes conformation and fusion of viral envelope+endosomal membrane occurs
Glycosylation is what?
ER and golgi proteins of Influenza that make up the envelope get set up near underside of cell membrane.
How are HA and NA attached to new Influenza viruses?
expressed on cell surface after glycosylation prior to budding.
Where does Influenza NA come into play?
cleave the sialic acid receptors from cell surface to new viruses won't rebind to dying cell
What does newly formed Influenza budded viruses need besides NA cleavage?
What does tryptase Clara do to new Influenza viruses?
cleaves HA to allow it to undergo conformational change in order to all fusion and endosome escape
Why is Influenza confined to the respiratory tract?
needs clara cells
Is CD8+ Tcell immunity to Influenza long lived?
Nope, can be boosted by repeated exposure
are CD8 cells cross reactive between Type A and B subtypes?
Nope. only between type A subtypes
Body develops Abs to Influenza?
Yes, HA and NA
What is antigenic drift in Influenza?
different strains WITHIN a subtype
How does antigenic drift in Influenza occur?
errors of replication
Where would antigenic drift in Influenza be advantageous?
If it occurs in HA or NA so the human antibodies can no longer recognize them
Abs bind to epitopes within how many HA sites?
What happens once all 5 sites of the Influenza antigenic sites have mutated?
almost no one in the world have pre-existing antibodies against it and you get an epidemic.
T/F? new Influenza strains replace older strains?
True. Except maybe when H1N1 escaped from a vault in Russia.....
2 vaccines to target HA and NA to do what in Influenza?
HA to block attachment
NA to block release
Influenza vaccine has 3 types, they are?
Influenza A H1N1 H3N2
After Influenza vaccine grown in eggs, what is done to them?
chemically inactivated/detergent disrupted (cut up)
T/F? Influenza vaccine induces cytotoxic T-cell response?
Nope. Only antibodies
How long to prepare a Influenza vaccine?
Influenza antiviral ion channel blocker does what?
inhibit function of M2 ion channel, prevent endosome escape of RNPs
What does M2 on the Influenza virus do?
decreases pH within endosome so envelope can fuse with it and release genome into cell
What does amantadine and rimantadine do in Influenza?
blocks M2 ion, prevent release of genome of Influenza virus
does amantadine and rimantadine work on H5N1?
does amantadine and rimantadine doesn't work on? H__N__?
Does does amantadine and rimantadine work on influenza type B?
Why don't you use does amantadine and rimantadine for everyone?
resistance arrises fast
Who do you give does amantadine and rimantadine?
children and elderly
What does Relenza and Tamiflu do?
Does Relenza and Tamiflu work against Type A +B?
does Relenza and Tamiflu prevent disease?
Nope. reduces duration.
When do you have to give Relenza and Tamiflu? how often?
within 2 days of symptoms, bid
orally as prodrug
What is antigenic shift?
Sudden appearance of new Influenza A virus of a new HA or NA
How does new HA get to humans usually?
Zoonosis from birds
Pandemics are rare because of Sialic acid... explain:
virus sees SA a2-6, avian virus sees SA2-3, but you only need single amino acid change to change that.
What is reassortment in influenza?
swapping of genes upon confection of a single cell.
example of reassortment in influenza?
Bird plus human viruses both infect pig, remixes and get a virus that had bird genes but can infect humans.... holy shit.
Deaths in 1918-1919 flu pandemic killed which age group the most?
15-35 age group
Is H1N1 lethal?
Not highly but has greater ability to replicate in lungs
H1N1 kills old, young?
3 populations particularily vulnerable to influenza?
Did closing schools help to stop influenza spread?
What is so scary about H5N1 besides being fast spreading and poultry killer? so what?
it doesn't need Clara cells.... it can infect ALL CELLS including the brain... holy shit.