Influenza - Zeng Flashcards Preview

D&T 3 test 2 > Influenza - Zeng > Flashcards

Flashcards in Influenza - Zeng Deck (31):
1

Influenza contains lipid envelope containing what 2 viral membrane proteins

Hemagglutintin ( HA)
Neuroaminidase ( NA)

2

What does the nucleocore contain

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

3

What are the 3 types of influenza

A B C

4

What is influenza classification based on

- serologic cross-reactivity
- sequence similarity of M1 and NP

5

Which influenza type is considered harmful to humans

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

6

What are the subtypes in influenza type A

based on HA and NA

7

What are influenza type A have caused extensive outbreaks in humans

HA 1, 2, 3
NA 1, 2

H1N1
H3N2

8

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

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

9

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

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

10

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

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

11

What are 2 routes of transmission for flue

airborne droplets
contaminated surfaces

12

how does flu interact with human cell

HA and sialic acids

13

what is human receptor preference

alpha 2,6 linked sailic acids
alpha 2,3 linked sailic acid

14

Where is alpha, 2,6 found in humans

tracheobronchial epithelium ( upper and lower tracts)
type I pneumocytes

15

Where is alpha, 2,3 found in humans

distal bronchiole epithelium
type II pneumocytes

16

What is a reservoir for all A subtypes

Avian
- rarely infect humans directly

17

who does swine impact? what happens

humans and birds
- 'mixing vessels' for reassortment between avian and human viruses

18

How does HA influence viral infectivity

- cleavage of HA

- single basic amino acid cleavage
-- extracellular cleavage only
-- systemic viral replication

- multiple basic amino acid cleavage
-- intracellular proteases
-- viral replication

19

How does NA influence viral infectivity

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

20

what are systemic clinical features of flu

fever
malaise
headache
myalgia
no viremia

21

what are respiratory clinical features of flu

dry cough
sore throat
nasal congestion/clear discharge

22

what is a complication of flu in children

otitis media

23

what are other complication of flu in children

sinusitis
primary viral pneumonia

24

what are secondary bacterial pneumonia

step pneumo
S . aureus
H. flu

25

what is Reye's syndrome

aspirin to fever children

26

what is reye's syndrome

acute encephalopathy
fatty liver degeneration
rashes and vomiting
potentially lethal

27

What is used to treat flu A? MOA?

Amantadine and Rimantadine
-M2 inhibitors ( inhibits viral uncoating, replication)

28

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

Oseltamivir and Zanamivir
- NA inhibitor
- reduces risk for pneumonia

29

complications/ SA of vaccination

- allergy to egg antigens
- Guillain-Barre syndrome

30

what is guillian-barre syndrome

polyneuritis
- muscle weakness and paralysis

31

what are 3 types of vaccines

1. formalin
2. Detergent
3. Purified viral glycoprotein