23 - Negative Strand and DS RNA Viruses (Stapleton)

Question 1

naked - strand RNA viruses

Answer 1

reovirus

Question 2

enveloped - strand RNA viruses

Answer 2

orthomyxovirus
paramyxovirus
rhabdovirus
bunyavirus

Question 3

orthomyxovirus causes

Answer 3

influenza A, B, C

Question 4

orthomyxovirus characteristics

Answer 4

segmented genomes (8)
enveloped - strand
influenza type determined by proteins (HA and NA)

Question 5

each segment of orthomyxovirus

Answer 5

each segment encodes one influenza gene

Question 6

influenza attachment

Answer 6

HA precursor (HA0) is processed to HA1 and HA2 by serine protease in lung
HA1 attaches to human sialic acid with a 2,6 linkage

Question 7

influenza entry

Answer 7

enters endosome with low pH

M2 protein pumps protons into virion to facilitate uncoating

Question 8

influenza genome replication

Answer 8

occurs in nucleus

RDRP makes + strand copy (template to make more - strand)

Question 9

influenza egress

Answer 9

removal of sialic acids from surface by NA release virion

Question 10

antigenic drift

Answer 10

minor differences
influenza A and B
due to RDRP infidelity
causes regional epidemics

Question 11

antigenic shift

Answer 11

major differences
influenza A only!!
due to reassortment of HA and NA from other types
Species mixing (birds, humans)
pigs as mixing pot for new strains
causes pandemics

Question 12

pandemics of influenza

Answer 12

have avian and swine connection
antigenic shift
seasonal (winter)

Question 13

barriers preventing spread from fowl to pigs and humans

Answer 13

humans have 2,6 linkage, birds have 2, 3 linkage
HA on virions in pro protein form, requires proteases in trachea and lung to process into infectious form
single amino acid residues increases replication (PB2)

Question 14

transmission of flu

Answer 14

Aerosol droplets
replication in respiratory tract
desquamation of ciliated cells=influenza
also primary viral pneumonia with secondary bacterial infections, leading to bacterial pneumonia

Question 15

detection of flu

Answer 15

swab
viral culture
DFA antibody staining
RT-PCR
serology
rapid flu diagnostic test

Question 16

flu treatment

Answer 16

M2 ion channel inhibitors-amantadine

neuraminidase inhibitor

Question 17

neuraminidase inhibitor

Answer 17

block cell surface sialic acid to prevent cleavage and release of flu A and B

Question 18

flu vaccine

Answer 18

seasonal
inactivated trivalent vaccine
attenuated inhaled vaccin

Question 19

types of paramyxovirus

Answer 19

mumps
measles
parainfluenza
RSV
metapneumovirus

Question 20

paramyxovirus characteristics

Answer 20

enveloped
helical
non segmented
replicate in cytoplasm
transmitted by saliva, respiratory secretions

Question 21

paramyxoviruses that become systemic

Answer 21

mumps, measles

good immunity post infection

Question 22

mumps

Answer 22

swelling of cheeks and under jaw
parotitis
male sterility due to replication in testis

Question 23

measles

Answer 23

rubeola
koplik spots
high fevers
can progress to pneumonia or encephalitis

Question 24

causes of encephalitis from measles

Answer 24

infection of neurons
post infectious encephalitis
subacute sclerosing pan encephalitis (SSPE)

Question 25

mumps and measles treatment

Answer 25

no antiviral
live attenuated vaccine with rubella (MMR)
vaccine grown in chicken eggs

Question 26

parainfluenza 4

Answer 26

mild URI

Question 27

parainfluenza 1,2,3

Answer 27

severe RI
no treatment or vaccine
leading cause of croup

Question 28

RSV

Answer 28

bronchilitis
LRI
virus kills infected epithelial cells causing plugs of dead cells
no vaccine

Question 29

RSV symptoms

Answer 29

bronchiolitis (leading cause)
pneumonia
encephalitis
effecing immunocompromised and elderly
winter infeciton

Question 30

rhabdoviridae types

Answer 30

rabies virus

vesicular stomatitis virus

Question 31

rhabdoviridae characteristics

Answer 31

enveloped
helical
bullet shape
- strand RNA

Question 32

rabies transmission

Answer 32

from wild animals, unvaccinated domestic animals, bats
shed in saliva
passed through bites or aerosol in bat caves

Question 33

rabies disease process

Answer 33

virus enters through bite
replicates in muscle
infects peripheral nerve and moves retrograde
replicates in DRG and travels up spinal cord
infects brain
virus travels back down nerves

Question 34

pathology of rabies

Answer 34

negri bodies (inclusion bodies) in cytoplams

Question 35

rabies treatment/prevention

Answer 35

no antiviral treatment
post exposure prophylaxis-wound care, passive immunization (human immunoglobulins), active immunization (killed virus)
pre exposure prophylaxis (killed virus vaccine)

Question 36

bunyavirus

Answer 36

infects humans and animals

Question 37

types of bunyavirus

Answer 37

hantavirus (sin nombre-4 corners, sin nombre like-yosemite)
california encephalitis
la crosse virus

Question 38

hantavirus

Answer 38

zoonosis
carried by deer mice
spread to humans through aerosolization of virus in rodent excreta

Question 39

la crosse virus

Answer 39

arbovirus
amplifying host in small mammals
vector of mosquitoes or ticks
dead end host in human
causes encephalitis

Question 40

reoviridae types

Answer 40

reovirus

rotavirus

Question 41

reoviridae structures

Answer 41

naked
icosahedral
dsRNA
segmented

Question 42

rotavirus characteristics

Answer 42

fecal oral spread
no antiviral
2 vaccines (3 doses)

Question 43

rotavirus infections

Answer 43

infants and young children
severe gastroenteritis
high infant mortality due to dehydration
damage to intestinal epithelium