Influenza

Question 1

how many classes of influenza virus

Answer 1

3- A B C

Question 2

which classes of influent cause human disease

Answer 2

A and B

Question 3

which influenza is responsible for pandemic outbreaks

Answer 3

influenza A

Question 4

what are influenza virus’

Answer 4

avian viruses that adapt to humans

Question 5

how is influenza spread

Answer 5

through aerosol droplets

Question 6

where does influent establish infections

Answer 6

establishes cytolytic infections in the epithelial of the upper and lower respiratory tract

Question 7

influenza A shape

Answer 7

spherical or rod-shaped

Question 8

structure of influenza A

Answer 8

spherical or rod-shaped enveloped virus covered with 2 spike like glycoproteins

Question 9

name the 2 spike like glycoproteins

Answer 9

trimeric hemagglutinin (HA)

tetrameric neuraminidase (NA)

Question 10

trimeric hemagglutinin

Answer 10

mediates binding to cell surfaces and internalisation

Question 11

tetrameric neuraminidase

Answer 11

NA cleaves silica acid and promotes viral release from the cells

Question 12

NA

Answer 12

neuraminidase

Question 13

HA

Answer 13

hem agglutinin

Question 14

DNA inside influenza

Answer 14

RNA

Question 15

influenza infection cycle

Answer 15

1) HA mediates binding to cell via sialic acid
2) endocytosis of virus
3) uncoating
4) RNA replication
4) viral proteins production
5) Budding
6) viral release promoted by NA

Question 16

influenza genotypes are..

Answer 16

diverse in birds

Question 17

influenza genotypes in birds express

Answer 17

variety of HA and NA subtypes

Question 18

types of HA expressed in birds

Answer 18

H1 to H15

Question 19

types of NA expressed in birds

Answer 19

N1- N9

Question 20

avian viruses prefer receptors found where

Answer 20

intestinal cells

Question 21

what do avian virus’ bind to on intestinal cells

Answer 21

alpha-2,3

sialic acid linkage to galactose

Question 22

what do human viruses prefer receptors found where

Answer 22

respiratory epithelia

Question 23

what do human virus’ bind to on respiratory epithelial cells

Answer 23

alpha-2,6 sialic acid linkage to galactose

Question 24

pigs

Answer 24

express both types of linkage on respiratory epithelial cells

Question 25

where doe influenza virus enter human poulations

Answer 25

where humans, pigs and birds (waterfowl) are in close proximity

Question 26

pigs can be infected with

Answer 26

both human and avian influenza

Question 27

how do pigs mediate the production of zoonotic influenza

Answer 27

Pigs can be infected with both human and avian influenza, and exchange of segments between viral genomes in the pig can give rise to variants expressing novel surface proteins together with human-adapted virulence determinants

Question 28

antigenic drift

Answer 28

occurs due to point mutation s which accumulate in survive HA and NA - meaning that the neutralising antibodies no longer recognise the virus

Question 29

point mutations in HA and NA lead to

Answer 29

antigenic drift

Question 30

antigenic drift leads to

Answer 30

epidemics

Question 31

when do pandemics occur

Answer 31

due to antigenic shift

Question 32

antigenic shift

Answer 32

when avian influenza viruses and human influenza viruses infect pigs. reassortment of the two genomes leads to expression of avian HA or NA in a virus otherwise adapted to infect humans

Question 33

antibodies

Answer 33

block viral attachment to host cells prevent release of new virions

Question 34

which cells destroy infected influenza cells

Answer 34

CD8 T cells

Question 35

human infections are usually caused by viruses that express

Answer 35

H1 H2 H3 N1 N2 N8 subtypes

Question 36

name three influenza pandemics

Answer 36

spanish flu asian flu hong kong flu

Question 37

spanish flu caused by

Answer 37

H1N1 (1918-1920)

Question 38

asian flu caused by

Answer 38

H2N2 (1950s)

Question 39

Hong kond fl caused by

Answer 39

H3N2 (1968-70)

Question 40

how many deaths in the 21st century have been caused by influenza viruses

Answer 40

from between 2 million to 1billion

Question 41

a 21st century global influenza pandemic analogous to the spanish flu is though to be

Answer 41

inevitable

Question 42

spanish flu happened in

Answer 42

1918

Question 43

which influenza subtype caused spanish flu

Answer 43

H1N1

Question 44

the spanish flu's victims were

Answer 44

health you adults >50% between 20 and 40 years old)

Question 45

why was the spanish flu outbreak different to other flu outbreaks

Answer 45

due to most outbreaks killing young, elderly and weak patients

Question 46

how many people died due to spnaish flu

Answer 46

50 mill to 100 mill

Question 47

how many people killed by spanish flu in first 25 weeks

Answer 47

25 million | aids killed 25 million in first 25 years

Question 48

why so many people killed by spanish flu

Answer 48

extremely high infection rates and hypokcytokinemia (thought to cause such extremes symptoms)

Question 49

hypercytokinemia

Answer 49

cytokine strom

Question 50

cytokine storm

Answer 50

systemic expression of a healthy and vigour immune system

Question 51

what causes cytokine storm

Answer 51

release of over 150 inflammatory mediators

Question 52

sepsis causes

Answer 52

systemic inflammation and coagulation

Question 53

which infections cause cytokine storms

Answer 53

avain influenza, ARDS, sepsis and ebola

Question 54

why is 21st century flu pandemic inevitable?

Answer 54

Highly Pathogenic Avian Influenza (HPAI) viruses, which express H5, H7 or H9, have become established in poultry throughout China and Southeast Asia HPAI H5N1 viruses were transmitted to individuals exposed to poultry during outbreaks in Hong Kong in 1997 These have spread, primarily through migratory birds, to infect poultry and humans in the Middle East and northern Africa Human transmission of H5N1 is infrequent, but mortality approaches 60% Pigs in China have been infected with avian H5N1 strain and the human H3N2 virus strain (responsible for the 1968-70 HK pandemic) This may facilitate the re-assortment of viral genome segments to produce a more transmissible virus

Question 55

Influenza A pandemic (2009)

Answer 55

caused by a tripe re-assortment influenza A virus (H1N1) compose of human , swine and eurasian avian strain -Efficient human-to-human transmission allows global spread of the virus