Influenza

Question 1

What are a major cause of death in the USA and worldwide?

Answer 1

Pneumonias, both viral and bacterial

Question 2

What are a major cause of pneumonia?

Answer 2

Influenza viruses

Question 3

How does influenza causes penumonia?

Answer 3

By direct viral pneumonia infection or by weakening immune system making it suceptipal to a secondary bacterial pneumonia

Question 4

Influenca virus if from what family?

Answer 4

orthomyxovirus family

Question 5

How is influenza virus packaged?

Answer 5

enveloped making it succeptable to drying

Question 6

what type of genome does influenza have?

Answer 6

it has 8 segments of (-)ssRNA

Question 7

What is signifigant about the 8 segments of its genome?

Answer 7

Easy to mix and match with other virus and mutate

Question 8

Because influenza is (-)ssRNA, what must it bring with it?

Answer 8

Must bring a functional RNA dependent RNA polymerase into hots to replicate

Question 9

What is the RNA dep, RNA poly used for? Two things.

Answer 9

To make mRNA for protein production and to replicate genome

Question 10

How are each of the 8 segments of genome packaged?

Answer 10

each is in its own protein capsid.

Question 11

What is N protein?

Answer 11

Neuraminidase, spike protein

Question 12

What is H protein?

Answer 12

Hemagglutinin, spike protein

Question 13

What does H protein do?

Answer 13

Allows viral attachment to host cell

Question 14

What does N protein do?

Answer 14

Allow viral budding off from host cell

Question 15

What is is antigenic shift?

Answer 15

Mix and match of different segments of genome of influenza

Question 16

what is the danger of antigenic shift?

Answer 16

pandemic, a worldwide epidemic.

Question 17

What is a pandemic?

Answer 17

worldwide epidemic with high morbidity and mortality

Question 18

What is a point mutation?

Answer 18

simple mistake of a different aa at a critical site.

Question 19

Why are point mutations importaint?

Answer 19

if they happen near spike protein region, it can affect antibody interaction.

Question 20

How do antibodies neutralize virus?

Answer 20

by covering spikes with antibodys

Question 21

What it is called when point mutation occurs that disallows ab binding but still allows infection?

Answer 21

antigenic drift, this is why we can get flu year after year

Question 22

What is an epidemic?

Answer 22

disease above the ususal endemic rate.

Question 23

What is an endemic?

Answer 23

normal rate of disease in area or country

Question 24

what mutation causes epidemics?

Answer 24

antigenic drift.

Question 25

Where does influenza RNA replicate?

Answer 25

Nucleus, that is strange, other RNA viruses will use the cytoplasm

Question 26

How often does a pandemic ususally occur?

Answer 26

every 25 to 40 years.

Question 27

avian influenza

Answer 27

H5N1

Question 28

How does antigenic shift happen to influenza A?

Answer 28

two or more strains infect same cell and swap segments.

Question 29

How does nuraminidase help viral release/budding?

Answer 29

by cleaving neuraminic acid on cell surface

Question 30

What does influenza virus do to RBCs?

Answer 30

they agglutinate RBCs, use this to find if body has antibodies to certain strain.

Question 31

what cells does influenza typically infect?

Answer 31

lung epithelial cells

Question 32

What is the bodys initial response to influenza infection?

Answer 32

Cytokines: IFN a and IFN b, innate immune responses.

Question 33

what are many deaths from influenza caused by?

Answer 33

seconday lung infection by bacteria because Tc cells kill lots of lung epithelial cells to get rid of virus., Staph and strep.

Question 34

How many H proteins are there?

Answer 34

16 Hs

Question 35

How many types of N spike proteins are there?

Answer 35

9 Ns

Question 36

how many types of influenza?

Answer 36

Type A that infects animals and humans, Type B that infects humans only and type C that is pretty mild.

Question 37

What type of influenza does vaccine ususally have?

Answer 37

Two versions of type and and one type B, trivalent.

Question 38

What type of vaccine is the mist?

Answer 38

cold adapted live, attenuated influenza virus vaccine.

Question 39

What are antivirals that are used only agains type A influenza?

Answer 39

Amatadine and rimatadine - work by blocking uncoating.

Question 40

What does tseltamivir and zanamivr (tamaflu and Relenza) do to flu virus?

Answer 40

inhib neuraminidase and viral release.

Question 41

what genome is more mutatable? RNA or DNA

Answer 41

RNA genome is more prone to mismatch because there isn't a spell check mechanism like in DNA

Question 42

What is influenza?

Answer 42

Highly infectous viral illness

Question 43

How many died in pandemic of 1918-1919?

Answer 43

50-100 million.

Question 44

What determines a Type A influenza virus?

Answer 44

Its H and N spike proteins

Question 45

What does Type B influenza infect?

Answer 45

Humans only, ususally young and old, mild epidemics

Question 46

What does Type A invluenza infect?

Answer 46

Humans and animals, all ages, pandemics and epidemics, moderate to severs

Question 47

How is influenza spread?

Answer 47

Respiratory droplets, infectious for 5-10 days, and hands

Question 48

Signs and symptoms of inflenza?

Answer 48

feaver, myalgia, sore throat, UNPRODUCTIVE caugh

Question 49

Fatality rate of influenza?

Answer 49

.5 per 1000 cases, low per infection but lots get infected.

Question 50

what is the most dangerous vector for influenza?

Answer 50

ducks are carriers

Question 51

Temporal pattern of influenza infections?

Answer 51

peaks in winters: Vit D, Kids all snotty in school

Question 52

How effective is the vaccine?

Answer 52

60% of the people exposed to virus that would have gotten it wont get it. It only