Flashcards in Influenza Deck (77):
1
How does chest x-ray look with seasonal flu?
normal
2
how long does acute infection of seasonal flu?
7 days, cough lasts a few weeks
3
at risk groups for seasonal flu?
young, old
4
incubation (days) of seasonal flu?
1-5 days
5
infectiousness of seasonal flu (days)??
5-6 days
6
deaths worldwide from seasonal flu?
1/4 to 1/2 MILLION
7
Influenza binds to what on non-ciliated respiratory epithelium?
sialic acid sugar
8
What kind of linkage on the sialic acid is it to galactose?
alpha 2-6
9
Flu spreads from infection site?
Nope. Localized.
10
Which airways does influenza like to replicate?
larger airways
11
what cytokine causes malaise, head and muscular aches?
IFNs
12
What cytokine causes fever?
IL-1
13
where is ciliated epithelium in respiratory system?
trachea and bronchi
14
Do you normally get viral pneumonia with flu?
Nope, usually due to secondary bacterial infections after cilia destruction
15
Influenza have envelopes?
Yes
16
Influenza and Rotavirus has what kind of genome?
single stranded -ve sense RNA
17
T/F?Influenza B can infect other species but only A is humans
False. B infects humans only, A infects other species
18
Influenza C is a major problem these days?
Naw. minor pathogen bro.
19
HA and NA for Influenza stands for?
haemagglutinin
Neuraminidase
20
What does NS1 the non-structural protein in Influenza do?
anti-interferon activity
21
how man gene segments in Influenza? encodes how many proteins?
8 segments encode 10+ proteins
22
how many polymerase subunits does Influenza come packaged with per RNP?
3
23
What is RNP in Influenza?
Ribonucleoproteins
24
HA is the snipper in Influenza?
Nope, the gripper
25
NA is the gripper or snipper in Influenza?
snipper
26
How many subtypes of HA and NA do we know of for Influenza?
17 HA
9NA
27
how many subtypes of HA and NA are there for Influenza B?
Only ONE.
28
What are the ancestral hosts of Influenza A?
aquatic birds
29
Current Influenza A subtypes in humans are?
H1N1
H3N2
30
How is Influenza taken into the cell?
receptor mediated endocytosis
31
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
32
Glycosylation is what?
ER and golgi proteins of Influenza that make up the envelope get set up near underside of cell membrane.
33
How are HA and NA attached to new Influenza viruses?
expressed on cell surface after glycosylation prior to budding.
34
Where does Influenza NA come into play?
cleave the sialic acid receptors from cell surface to new viruses won't rebind to dying cell
35
What does newly formed Influenza budded viruses need besides NA cleavage?
tryptase Clara
36
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
37
Why is Influenza confined to the respiratory tract?
needs clara cells
38
Is CD8+ Tcell immunity to Influenza long lived?
Nope, can be boosted by repeated exposure
39
are CD8 cells cross reactive between Type A and B subtypes?
Nope. only between type A subtypes
40
Body develops Abs to Influenza?
Yes, HA and NA
41
What is antigenic drift in Influenza?
different strains WITHIN a subtype
42
How does antigenic drift in Influenza occur?
errors of replication
43
Where would antigenic drift in Influenza be advantageous?
If it occurs in HA or NA so the human antibodies can no longer recognize them
44
Abs bind to epitopes within how many HA sites?
5 sites
45
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.
46
T/F? new Influenza strains replace older strains?
True. Except maybe when H1N1 escaped from a vault in Russia.....
47
2 vaccines to target HA and NA to do what in Influenza?
HA to block attachment
NA to block release
48
Influenza vaccine has 3 types, they are?
Influenza B
Influenza A H1N1 H3N2
49
After Influenza vaccine grown in eggs, what is done to them?
chemically inactivated/detergent disrupted (cut up)
50
T/F? Influenza vaccine induces cytotoxic T-cell response?
Nope. Only antibodies
51
How long to prepare a Influenza vaccine?
6 months
52
Influenza antiviral ion channel blocker does what?
inhibit function of M2 ion channel, prevent endosome escape of RNPs
53
What does M2 on the Influenza virus do?
decreases pH within endosome so envelope can fuse with it and release genome into cell
54
What does amantadine and rimantadine do in Influenza?
blocks M2 ion, prevent release of genome of Influenza virus
55
does amantadine and rimantadine work on H5N1?
Nope.
56
does amantadine and rimantadine doesn't work on? H__N__?
H5N1
57
Does does amantadine and rimantadine work on influenza type B?
Nope
58
Why don't you use does amantadine and rimantadine for everyone?
resistance arrises fast
59
Who do you give does amantadine and rimantadine?
children and elderly
60
What does Relenza and Tamiflu do?
block NA
61
Does Relenza and Tamiflu work against Type A +B?
Yes both
62
does Relenza and Tamiflu prevent disease?
Nope. reduces duration.
63
When do you have to give Relenza and Tamiflu? how often?
within 2 days of symptoms, bid
64
Relenza administered?
inhalation
65
Tamiflu admin?
orally as prodrug
66
What is antigenic shift?
Sudden appearance of new Influenza A virus of a new HA or NA
67
How does new HA get to humans usually?
Zoonosis from birds
68
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.
69
What is reassortment in influenza?
swapping of genes upon confection of a single cell.
70
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.
71
Deaths in 1918-1919 flu pandemic killed which age group the most?
15-35 age group
72
Is H1N1 lethal?
Not highly but has greater ability to replicate in lungs
73
H1N1 kills old, young?
young adults!
74
3 populations particularily vulnerable to influenza?
prey women
obese
indigenous
75
Did closing schools help to stop influenza spread?
nope.
76
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.
77