Lecture 12--resp/emerging viral

Question 1

enveloped RNA virus with segmented genome

Answer 1

influenz

Question 2

two types of spike proteins on envelope of flu virus:

Answer 2

hemagglutinin and neuraminidase

Question 3

role of hemagglutinin?

Answer 3

recognize, attach to receptors on resp tract epithelial cells

Question 4

role of neuraminidase?

Answer 4

degrade protective mucus coating resp tract allowing virus reach host cell surface, help release newly formed mature virus

Question 5

most common type flu?

Answer 5

type A, most severe and broad host range

Question 6

type A has __ diff H types, ___ diff N types

Answer 6

18; 11

Question 7

what is shifting?

Answer 7

segmented genome allow H and N genes reassort if two diff flu subtypes infect same host cell at same time (progeny is mix, new subtype)

Question 8

what is drifting?

Answer 8

during virus replication, random mutations occur in H or N genes, result in minor changes (progeny just slightly diff)

Question 9

shifting facilitated in areas where ____

Answer 9

agricultural practices involve close human animal contact

Question 10

type A has ___ day incubation, __ day symptoms, __ week recovery

Answer 10

1-3; 4-8; 1-2

Question 11

type A is contagious __ day before symptoms, ___ day after symptoms

Answer 11

1; 5

Question 12

characteristics of flu

Answer 12

high fever, headache, pains, fatigue, chest discomfort and coughing

Question 13

how diagnose flu in lab?

Answer 13

nasopharyngeal swab (within 5 days of onset of symps)

Question 14

main lab test for flu?

Answer 14

PCR

Question 15

HOW DOES TAMIFLU AND RELENZA WORK?

Answer 15

block neuraminidase activity, work best in 1 or 2 days, reduce severity/duration, only given if hospitalized/severe complications

Question 16

what’s in flu vaccine?

Answer 16

killed whole virus or purified H and N proteins

Question 17

how effective is vaccine?

Answer 17

50-60%

Question 18

why not so effective?

Answer 18

flu virus changes, diff patients respond diff (health factors)

Question 19

why need get flu shot every year?

Answer 19

antibodies developed last year are gone, new flu strains not in last year

Question 20

who should get vaccine

Answer 20

> 6mths, nursing homes, healthy >50, healthcare workers

Question 21

enveloped RNA virus with pleomorphic morphology, hemorrhagic fever virus

Answer 21

ebola

Question 22

mechanism of ebola?

Answer 22

replicate in WBC, spread via lymph, secondary infections throughout body, transmit with blood/body fluids

Question 23

how care for ebola?

Answer 23

fluid replacement, maintain electrolyte balance

Question 24

traits of emerging diseases?

Answer 24

usually start zoonotic, sustained by human to human transmission, international outbreak possible, combatting is challenging

Question 25

do viruses meet NASA definition of life?

Answer 25

yes, self sustaining chem system capable of Darwinian evolution

Question 26

where viruses come from?

Answer 26

retrograde, cell origin, parallel evolution?

Question 27

what is missing link?

Answer 27

mimivirus (of amoebas), large

Question 28

__% of human genome is virus

Answer 28

8