Lecture 20: Togaviruses

Question 1

What is the primary target for arteriviruses

Answer 1

macrophages

Question 2

t or f: persistent infections with arteriviruses possible

Answer 2

true

Question 3

what does equine arteritis virus cause

Answer 3

reproductive and respiratory disease

Question 4

how frequently is equine arteritis virus monitored and how long do you have to notify state vet of suspected case

Answer 4

monitored monthly
Report state AZ state vet in 24hrs

Question 5

what does porcine reproductive and respiratory syndrome cause

Answer 5

reproductive and respiratory disease

Question 6

how often is porcine reproductive and respiratory syndrome monitored

Answer 6

monthly

Question 7

equine arteritis virus is short lived outside host but can persist for years in __ and __

Answer 7

frozen tissues and body fluids (ex: semen)

Question 8

how is EAV transmitted

Answer 8

1. Aerosol- primarily during acute phase infeciton
2. Sexual transmission- persistently infected stallions
3. Vertical transmission- in pregnant mares

Question 9

what is pathogenesis of EAV

Answer 9

1. Virus targets URT/LRT
2. Replicating in epithelium, tonsils and macrophages
3. Migration to regional LN
4. Viremia
   5, localization of vascular endothelium- panvasculitis
5. Inflammation/necrosis of affected vessels
6. Edema/hemorrhage, abortion in pregnant mares

Question 10

who are carriers for EAV

Answer 10

stallions

Question 11

EAV in __dependent in stallions

Answer 11

testosterone

Question 12

EAV in stallions is linked to __ cell subtype

Answer 12

CD3+ T cell subtype

Question 13

what Are some clinical signs of EAV

Answer 13

1. Fever 106
2. Dependent edema
3. Conjunctivitis
4. Serous/mucoid nasal d/c
5. Petechial hemorrhage
6. Fatal pneumonitis/ pneumoenteritis in foals

Question 14

recently bred mare develops the following signs- periorbital edema, petechiae hemorrhages, fever. What is likely cause

Answer 14

EAV

Question 15

what is test of choice to dx EAV

Answer 15

complement enhanced virus neutralization assay in guinea pigs

Question 16

how can you manage EAV in stallions

Answer 16

1. Castration because testosterone dependent
2. GnRH vaccines- limit shedding in semen

Question 17

EAV vaccine is risk based and prevents __in mares but animals are now __

Answer 17

abortion, seropositive (DIVA incompatible)

Question 18

piglets born to sows with porcine reproductive and respiratory virus are __

Answer 18

congenitally persistently infected

Question 19

what is pathogenesis of porcine reproductive and respiratory virus

Answer 19

1. Aerosol exposure
2. Virus targets URT/LRT
3. Replicating in epithelium, tonsils, macrophages
4. Migration to LN
5. Viremia
6. Targeting alveolar macrophages resulting in interstitial pneumonia, and secondary infections

Question 20

what are some signs of reproductive failure syndrome for PRRV

Answer 20

SMEDI, agalactia, thumping respiratory pattern in suckling piglets

Question 21

what are some signs of post-weaning respiratory diseases in PRRV

Answer 21

blue ear disease- cyanosis

Question 22

recently weaned pig with the following ear lesion- what likely cause

Answer 22

PRRV

Question 23

ELISA for PRRV is not able to identify __

Answer 23

carriers

Question 24

answer kahoot

Answer 24

mycoplasma hyorhinis

Question 25

how do you prevent PRRV

Answer 25

vaccines- offer partial protection

Question 26

what is tx for PRRV

Answer 26

no effective tx- can try anti-inflammatories and B-vitamins

Question 27

togaviruses are considered arbor viruses, capable of infecting __ and __

Answer 27

insects and animal hosts

Question 28

what is mode of transmission for toga viruses

Answer 28

mosquitoes- biological vector

Question 29

where is EEEV found

Answer 29

east of Mississippi River

Question 30

where is WEEV found

Answer 30

west of Mississippi River, but no cases in NA for 15yrs

Question 31

where is VEEV found

Answer 31

central and South America (notifiable disease in US)

Question 32

what is enzootic cycle of EEEV

Answer 32

circulation in songbirds/wading birds and spread to mosquito species via feeding on birds

Question 33

what is epizootic cycle of EEEV

Answer 33

spillover into human and horses via bridge vectors (mosquitoes)

Question 34

Human and horses are dead end hosts for __ and __, but not __

Answer 34

EEE/WEE not VEE

Question 35

What is pathogenesis of EEEV and other toga viruses

Answer 35

1. Macrophage clearance and relocation into peripheral LN
2. Replication and viremia
   3, endothelial cell infection—> neuronal infection in CNS

Question 36

what are signs of EEEV and other togaviruses in horses

Answer 36

fever, fatal encephalomyelitis, circling, depression, cortical blindness, paralysis, death

Question 37

what are some signs of EEEV and other togaviruses in exotic avians

Answer 37

encephalitis, torticollis, leg paralysis, fever

Question 38

how do you dx EEEV and other togaviruses

Answer 38

1. Clinical hx- acutely neurological in summer/early fall
2. CSF- pronounced neutrophilia (pathopneumonic for EEEV)
3. Rt-PCR

Question 39

what is tx for EEEV and other toga viruses

Answer 39

Fever reduction- ice baths
Hydration
Anti-inflammatories
Seizure control- diazepam

Question 40

how do you prevent and control EEEV and other togaviruses

Answer 40

1. Vaccinate
2. Mosquito control and prevention
3. Quarantine horses for VEEV

Question 41

t or f: all togaviruses like EEE, WEE and VEE are notifiable? Which is considered FAD

Answer 41

true
FAD: VEEV

Question 42

answer kahoot

Answer 42

rabies

Question 43

Answer kahoot

Answer 43

EHD

Question 44

answer kahoot

Answer 44

WEE

Question 45

answer kahoot

Answer 45

macrophages

Question 46

answer kahoot

Answer 46

neutrophils