Influenza - Zeng

Question 1

Influenza contains lipid envelope containing what 2 viral membrane proteins

Answer 1

Hemagglutintin ( HA)

Neuroaminidase ( NA)

Question 2

What does the nucleocore contain

Answer 2

8-RNA segment
Nuclear matrix protein (M1)
nucleoprotein (NP)

Question 3

What are the 3 types of influenza

Answer 3

A B C

Question 4

What is influenza classification based on

Answer 4

• serologic cross-reactivity

- sequence similarity of M1 and NP

Question 5

Which influenza type is considered harmful to humans

Answer 5

A and B

- C can cause disease in human but not serious human health concern

Question 6

What are the subtypes in influenza type A

Answer 6

based on HA and NA

Question 7

What are influenza type A have caused extensive outbreaks in humans

Answer 7

HA 1, 2, 3
NA 1, 2

H1N1
H3N2

Question 8

What is antigenic drift? what types does it occur in? what does it cause?

Answer 8

• point mutations in HA and NA
• A and B
• epidemic infuenza
• occurs gradually

Question 9

What is antigenic shift? what types does it occur in? what does it cause?

Answer 9

• reassortment of genomic RNA segments
• A only
• pandemic influenza
• sudden changes in HA andNA

Question 10

When does flu most commonly occur? and why at this time?

Answer 10

winter and early spring
December to March
- low temp and low humidity

Question 11

What are 2 routes of transmission for flue

Answer 11

airborne droplets

contaminated surfaces

Question 12

how does flu interact with human cell

Answer 12

HA and sialic acids

Question 13

what is human receptor preference

Answer 13

alpha 2,6 linked sailic acids

alpha 2,3 linked sailic acid

Question 14

Where is alpha, 2,6 found in humans

Answer 14

tracheobronchial epithelium ( upper and lower tracts)
type I pneumocytes

Question 15

Where is alpha, 2,3 found in humans

Answer 15

distal bronchiole epithelium

type II pneumocytes

Question 16

What is a reservoir for all A subtypes

Answer 16

Avian

- rarely infect humans directly

Question 17

who does swine impact? what happens

Answer 17

humans and birds

- ‘mixing vessels’ for reassortment between avian and human viruses

Question 18

How does HA influence viral infectivity

Answer 18

• cleavage of HA
• single basic amino acid cleavage
• • extracellular cleavage only
• • systemic viral replication
• multiple basic amino acid cleavage
• • intracellular proteases
• • viral replication

Question 19

How does NA influence viral infectivity

Answer 19

• cleavage of sialic acids from glycoprotein
• release virions from infected cells
• prevent viral aggregation in extracellular space to enhance viral disemination

Question 20

what are systemic clinical features of flu

Answer 20

fever
malaise
headache
myalgia 
no viremia

Question 21

what are respiratory clinical features of flu

Answer 21

dry cough
sore throat
nasal congestion/clear discharge

Question 22

what is a complication of flu in children

Answer 22

otitis media

Question 23

what are other complication of flu in children

Answer 23

sinusitis

primary viral pneumonia

Question 24

what are secondary bacterial pneumonia

Answer 24

step pneumo
S . aureus
H. flu

Question 25

what is Reye’s syndrome

Answer 25

aspirin to fever children

Question 26

what is reye’s syndrome

Answer 26

acute encephalopathy
fatty liver degeneration
rashes and vomiting
potentially lethal

Question 27

What is used to treat flu A? MOA?

Answer 27

Amantadine and Rimantadine

-M2 inhibitors ( inhibits viral uncoating, replication)

Question 28

What is used to treat flu A and B? MOA?

Answer 28

Oseltamivir and Zanamivir

• NA inhibitor
• reduces risk for pneumonia

Question 29

complications/ SA of vaccination

Answer 29

• allergy to egg antigens

- Guillain-Barre syndrome

Question 30

what is guillian-barre syndrome

Answer 30

polyneuritis

- muscle weakness and paralysis

Question 31

what are 3 types of vaccines

Answer 31

1. formalin
2. Detergent
3. Purified viral glycoprotein