10.28.2022. Flu: my questions

Question 1

describe the structure of influenza virus

Answer 1

• enveloped
• ss negative RNA
• segmented genome

Question 2

where do influenza viruses get their lipid envelope?

Answer 2

from host cells

Question 3

regarding the surface antigens, there is one thing that is essential for pathogenesis. what is it?

Answer 3

glycoproteins

Question 4

what is essential for pathogenesis in infleunza

Answer 4

glycoproteins

Question 5

what does H or HA antigen stand for?

Answer 5

hemagglutinin

Question 6

what does HA do?

Answer 6

aids in attachment to ciliated epithelial cells

Question 7

what does N or NA stand for?

Answer 7

neuraminidase

Question 8

what does NA do?

Answer 8

aids in release

Question 9

which H subtypes are spread in humans?

Answer 9

1,2,3

Question 10

which N subtypes are spread among humans?

Answer 10

1,2

Question 11

which two types of flu viruses cause seasonal epidemics in the US?

Answer 11

A and B

Question 12

what do A and B viruses cause in the US?

Answer 12

seasonal epidemics

Question 13

how are influenza A viruses divided into types?

Answer 13

based on H and N ex. H1N1

Question 14

host range and mutation rate for HA?

Answer 14

wide host range (birds, pigs, humans)
high mutation rate

Question 15

host range and mutation rate for NA?

Answer 15

narrow host range
lower mutation rate

Question 16

how are B viruses divided into subtypes?

Answer 16

by the location in which they were isolated ex. B/Victoria

Question 17

which flu virus is responsible for pandemics?

Answer 17

A

Question 18

are B viruses responsible for pandemics?

Answer 18

no

Question 19

are A viruses responsible for pandemics?

Answer 19

oftentimes yes

Question 20

incubation period of flu?

Answer 20

about two days

Question 21

name three symptoms of flu

Answer 21

headache, fever, sore throat, dry tight cough, chest pain, extreme fatigue, muscle aches, weakness, malaise.

Question 22

what is the most important symptom of the flu?

Answer 22

extreme fatigue

Question 23

who is most prone to developing a secondary infection and may need hospitalization?

Answer 23

ages 0-5, 65+

Question 24

name two syndromes that may occasionally develop as a result of flu

Answer 24

Reye’s syndrome

Guillain-Barre Syndrome

Question 25

Reye's syndrome results from ____

Answer 25

influenza

Question 26

Guillain-Barre Syndrome may develop from... what is it?

Answer 26

all kinds of viral infection. immune disorder

Question 27

how is influenza acquired/how does one get infected?

Answer 27

aerosolized respiratory secretions (droplets) or via fomite transfer

Question 28

what does the influenza virus attach to? how does it attach?

Answer 28

respiratory epithelium cells. HA glycoprotein on virus attaches to sialic acid on host respiratory epithelial cells.

Question 29

how does influenza virus enter the cell?

Answer 29

endocytosis

Question 30

how do mature virions exit the host cell?

Answer 30

budding

Question 31

does H&N type change in antigenic drift or shift?

Answer 31

shift

Question 32

antigenic drift: ______ influenza

Answer 32

seasonal

Question 33

antigenic shift: ________ influenza

Answer 33

pandemic

Question 34

how often do flu epidemics occur?

Answer 34

every year with seasonal influenza

Question 35

how often do flu pandemics occur?

Answer 35

periodically

Question 36

why do flu pandemics occur?

Answer 36

new strain = limited/no immunity = more cases = more deaths

Question 37

what is antigenic drift?

Answer 37

slow, constant changes as virus replicates.

Question 38

is antigenic drift fast or slow?

Answer 38

slow

Question 39

how do changes occur in antigenic drift?

Answer 39

mutations during replication

Question 40

what does better binding mean for flu viruses? what do mutations have to do with binding?

Answer 40

increased immunity. mutations weaken the binding each time.

Question 41

what is antigenic shift? what does it result in?

Answer 41

abrupt, major changes in a virus, resulting in changes to/new H and/or N type

Question 42

is antigenic shift fast or slow?

Answer 42

fast

Question 43

describe the host range of antigenic shift?

Answer 43

fast

Question 44

the inactivated flu vaccine is ---valent

Answer 44

tri or quad

Question 45

what antibodies are found in the inactivated flu vaccine?

Answer 45

IgG only

Question 46

how is the live attenuated vaccine administered?

Answer 46

nasal flu mist

Question 47

what antibodies are present in the live attenuated vaccine?

Answer 47

IgA and IgG

Question 48

who should the live attenuated vaccine administered to?

Answer 48

only for ages 2-49

Question 49

who should the inactivated vaccine be administered to?

Answer 49

egg-free or high does for >65 years

Question 50

what are the two options for the influenza vaccine?

Answer 50

inactivated vaccine live attenuated vaccine (nasal flu mist)