Influenza Flashcards by Jason Hsu

How does chest x-ray look with seasonal flu?

normal

How well did you know this?

Not at all

Perfectly

how long does acute infection of seasonal flu?

7 days, cough lasts a few weeks

How well did you know this?

Not at all

Perfectly

at risk groups for seasonal flu?

young, old

How well did you know this?

Not at all

Perfectly

incubation (days) of seasonal flu?

1-5 days

How well did you know this?

Not at all

Perfectly

infectiousness of seasonal flu (days)??

5-6 days

How well did you know this?

Not at all

Perfectly

deaths worldwide from seasonal flu?

1/4 to 1/2 MILLION

How well did you know this?

Not at all

Perfectly

Influenza binds to what on non-ciliated respiratory epithelium?

sialic acid sugar

How well did you know this?

Not at all

Perfectly

What kind of linkage on the sialic acid is it to galactose?

alpha 2-6

How well did you know this?

Not at all

Perfectly

Flu spreads from infection site?

Nope. Localized.

How well did you know this?

Not at all

Perfectly

Which airways does influenza like to replicate?

larger airways

How well did you know this?

Not at all

Perfectly

what cytokine causes malaise, head and muscular aches?

IFNs

How well did you know this?

Not at all

Perfectly

What cytokine causes fever?

IL-1

How well did you know this?

Not at all

Perfectly

where is ciliated epithelium in respiratory system?

trachea and bronchi

How well did you know this?

Not at all

Perfectly

Do you normally get viral pneumonia with flu?

Nope, usually due to secondary bacterial infections after cilia destruction

How well did you know this?

Not at all

Perfectly

Influenza have envelopes?

Yes

How well did you know this?

Not at all

Perfectly

Influenza and Rotavirus has what kind of genome?

single stranded -ve sense RNA

How well did you know this?

Not at all

Perfectly

T/F?Influenza B can infect other species but only A is humans

False. B infects humans only, A infects other species

How well did you know this?

Not at all

Perfectly

Influenza C is a major problem these days?

Naw. minor pathogen bro.

How well did you know this?

Not at all

Perfectly

HA and NA for Influenza stands for?

haemagglutinin

Neuraminidase

How well did you know this?

Not at all

Perfectly

What does NS1 the non-structural protein in Influenza do?

anti-interferon activity

How well did you know this?

Not at all

Perfectly

how man gene segments in Influenza? encodes how many proteins?

8 segments encode 10+ proteins

How well did you know this?

Not at all

Perfectly

how many polymerase subunits does Influenza come packaged with per RNP?

How well did you know this?

Not at all

Perfectly

What is RNP in Influenza?

Ribonucleoproteins

How well did you know this?

Not at all

Perfectly

HA is the snipper in Influenza?

Nope, the gripper

How well did you know this?

Not at all

Perfectly

NA is the gripper or snipper in Influenza?

snipper

How many subtypes of HA and NA do we know of for Influenza?

17 HA | 9NA

how many subtypes of HA and NA are there for Influenza B?

Only ONE.

What are the ancestral hosts of Influenza A?

aquatic birds

Current Influenza A subtypes in humans are?

H1N1 | H3N2

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?

tryptase Clara

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?

5 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 B | 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?

6 months

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?

Nope.

does amantadine and rimantadine doesn't work on? H__N__?

H5N1

Does does amantadine and rimantadine work on influenza type B?

Nope

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?

block NA

Does Relenza and Tamiflu work against Type A +B?

Yes both

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

Relenza administered?

inhalation

Tamiflu admin?

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?

young adults!

3 populations particularily vulnerable to influenza?

prey women obese indigenous

Did closing schools help to stop influenza spread?

nope.

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.

Is H5N1 in humans?

Only from humans with direct contact with birds. but about 440 cases, 60% death rate