Final; Respiratory Viruses

Question 1

What are the three types of influenza

Answer 1

A, B , and C (the most rare)

type A is the most common and associated with the greatest concern

Question 2

What is the genome of influenza

Answer 2

-ssRNA in 8 segments

Question 3

What type of virion is influenza

Answer 3

enveloped

Question 4

What are the special surface antigens of influenza

Answer 4

16 HA (hemagglutinin) serotypes
9 NA (neuraminidase) serotypes

Question 5

What is a major determinant for human to human transmission of influenza

Answer 5

HA

Question 6

Which type of influenza has an animal reservoir

Answer 6

type A; mostly waterfowl

the pig is a key between bird and human transmission

Question 7

True or False

HAs role is cell attachment and entry is poorly understood

Answer 7

False; it is well understood

Question 8

What triggers the conformation change after virus and host cell membrane attachment

Answer 8

pH change of the endosome

Question 9

The conformation change of the membranes triggered by the pH change causes what

Answer 9

membrane fusion; this is a model for all enveloped viruses

Question 10

Where does transcription of influenza take place

Answer 10

in the nucleus; exception to the rule (it has -ssRNA)

Question 11

The protected genome (RNP core) escapes the nucleus and buds from the cell via the use of this protein

Answer 11

NA

Question 12

How is influenza transmitted

Answer 12

aerosol, large and small droplets

Question 13

When is the infectivity the greatest for influenza particles

Answer 13

When they are the smallest, they can penetrate the deep lung

Question 14

What is the incubation period of influenza

Answer 14

1-4 days

contagious days before symptom onset to 5 days letters; children infectious for longer

Question 15

What are the symptoms of the seasonal flu

Answer 15

fever, malaise, nonproductive cough, sore throat

lasts 3 to 7 days after symptoms develop

Question 16

What are the current circulating strains of influenza and its contagiousness

Answer 16

H3N2, H1N1

reproductive numer = 1:2

Question 17

What are some complications of influenza

Answer 17

viral pneumonia
bacterial pneumonia
reye synrome (type B + aspirin)
otitis media

Question 18

What type of vaccine is the influenza vaccine

Answer 18

attenuated live; donor virus with wild type HA/NA epitopes

Question 19

Why is a new influenza vaccine required each year

Answer 19

antigenic shift, the vaccine usually contains H3N2, H1N1, and type B

Question 20

What is used to prevent/control influenza

Answer 20

antiviral treatment
tamiflu
supportive care

Question 21

What are the 4 major pandemics of influenza

Answer 21

1918 Spanish Flu (H1N1)
1957 Asian Flu (H2N2)
1968 Hong Kong Flu (H3N2)
2009-2010 H1N1

Question 22

Highly pathogenic avian influenza (HPAI) contains what strains (and low pathogenic)

Answer 22

H5 or H7; has multi-basic residues at HA cleavage sites allowing replication throughout the body (of birds)

Question 23

What are the symptoms of HPAI

Answer 23

skin lesions, necrotic and swollen combs, systemic infection (of birds)

Question 24

True or False

H5 and H7 strains can mutate to HPAI strains

Answer 24

True

Question 25

What is so controversial about the Dutch study involving H5N1

Answer 25

They used ferrets to model how H5N1 could infect humans which has a high mortality rate

Question 26

What is used to characterize the adenovirus

Answer 26

serotype; different serotypes are associated with different diseases

Question 27

What are the two most studied adenovirus serotypes

Answer 27

2 and 5

Question 28

What is the genome of adenovirus

Answer 28

dsDNA

Question 29

What is the virion of adenovirus

Answer 29

non-enveloped

Question 30

How does adenovirus enter the cell

Answer 30

entry is triggered by coxsackie-adenovirus receptor (CAR) | pH triggers capsid disassembly

Question 31

What is the method of gene expression of adenovirus

Answer 31

intermediate - early early late

Question 32

What takes place during the intermediate-early phase of gene expression in adenovirus

Answer 32

E1A portion of genome | 2 transcriptional regulators (cell and virus)

Question 33

What takes place during the early phase of gene expression in adenovirus

Answer 33

5 genome sections | DNA replication and post transcriptional events

Question 34

What takes place during late phase of gene expression in adenovirus

Answer 34

take over of cellular mRNA synthesis

Question 35

What takes place during genome replication of adenovirus

Answer 35

it can be initiated at either end of the genome 5'-3' displaced strand circularizes allowing template to be made primed by the protein pTP

Question 36

What is involved with cell cycle regulation of adenovirus

Answer 36

DNA replication occurs during S phase | not all cells are actively replicating

Question 37

What does the E1A portion of adenovirus do to gene expression

Answer 37

it inactivates pRb leading to S phase

Question 38

What does the E1B portion of adenovirus do to gene expression

Answer 38

it inactivates p53 leading to S phase and preventing apoptosis

Question 39

The E3 gene of adenovirus produces what

Answer 39

proteins important to host immune evasion; blocks MHC-1 expression

Question 40

E3 gene blocks what cytokines

Answer 40

TNF induced apoptosis | IFN-α and IFN-β keeping protein translation alive

Question 41

With adenovirus, what disease is common

Answer 41

respiratory infections; 5-10% of all viral infections

Question 42

What are the symptoms of adenovirus infections

Answer 42

common cold symptoms | nasal congestion, inflammation, cough

Question 43

adenovirus also causes this disease which causes severe pneumonia in military troops (vaccine available for them)

Answer 43

actue respiratory disease

Question 44

What makes adenovirus important involving research

Answer 44

it is frequently used as a vector

Question 45

This is a frequent cause of mild upper respiratory infections

Answer 45

rhinovirus

Question 46

Why is it impractical to develop a vaccine against rhinovirus

Answer 46

it has a large antigenic diversity; humans are the only reservoir

Question 47

What does rhinovirus use to attach to host cells

Answer 47

attached to intercellular adhesion molecule 1 or the very low density lipoprotein receptor and extrudes its genome into the cell

Question 48

What is the incubation/duration of rhinovirus

Answer 48

incubation is 1-4 days | duration 2-3 days with virus shedding sometimes up to 3 weeks

Question 49

What are the symptoms of rhinovirus diseases

Answer 49

red nose, nasal discharge, epithelial damage due to immune response

Question 50

What are the prevention strategies against rhinovirus

Answer 50

no vaccine | no antivirals; resistant mutants