Lecture 15: Rabies and vesicular stomatitis Flashcards

1
Q

How do you dx rabies

A

FA impression smears of midbrain, cerebellum and hippocampus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is geographic distribution of rabies virus vs bat lyssaviruses

A
  1. Rabies virus- worldwide besides Australia and Antarctica
  2. Bat lyssaviruses- Europe, Australia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

99% of human cases of rabies are transmitted by __

A

dogs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is pathogenesis of rabies

A
  1. Peripheral exposure- bit, contact with body fluids
  2. Infection of peripheral nerve endings
  3. Centripetal phase- retrograde axonal transport to dorsal ganglion
  4. Dissemination throughout CNS
  5. Centrifugal phase- spreads to salivary glands, eye, skin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is incubation period for rabies

A

3-12wks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what factors affect incubation period

A
  1. Host species
  2. Virus strain
  3. Dose exposure
  4. Exposure site
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what species are rarely susceptible to rabies

A

opossum, small rodents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how does exposure site affect incubation period for rabies

A

axonal transport has rate limit- the longer the axon the longer it takes to reach CNS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

1yr cow presents with hypersalivation, dysphagia and progresses to stargazing, ataxia, difficulty rising. What are you concerned about

A

rabies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are these and what virus are they indicative of

A

Negri bodies- rabies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how do you dx rabies in animal that bite

A
  1. Euthanize and FA testing
  2. 10 day isolation- if actively shedding rabies at time of bite then will die within 10 days
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

how do you prevent rabies

A
  1. Killed vaccines single dose at 14wks, 1yr, q1 or 3yrs
  2. Oral baits for wildlife
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is treatment for animal bitten by suspected rabid animal who has hx of rabies vaccine

A

booster and outpatient monitor 45d

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what is treatment for animal bitten by suspected rabid animal that is not vaccinated

A
  1. Euthanize if biting animal tests positive
  2. Long term inpatient monitoring (4months) if biting animal was not tested followed by vaccination
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how long do ferrets have to undergo inpatient monitoring if bitten by suspected rabid animal but unable to test biting animal

A

6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

why 4-6 months for inpatient monitoring of suspected rabies bite

A

4-6 months is upper limit of incubation period

17
Q

how long is quarantine period for animal that has bitten someone

18
Q

what are the vectors for rabies transmission in U.S. and worldwide

A

US- bats, skunks, raccoons
Outside US- dogs

19
Q

horse presents with these lesions what is top differential

A

vesicular stomatitis

20
Q

how is vesicular stomatitis virus transmitted

A
  1. Direct contact
  2. Biological vector-culicoides
21
Q

what are the two major serogroups of vesicular stomatitis virus

A

Indiana and New Jersey

22
Q

ruled out FMD what likely caused these lesions

A

vesicular stomatitis

23
Q

what are some clinical signs of vesicular stomatitis virus

A
  1. Vesicular lesions of tongue and oral cavity
  2. Hypersalivation and secondary infections
  3. Coronary band lesions-lameness
24
Q

what does a positive titer for vesicular stomatitis mean

A

could be prior exposure, do paired serology titer few weeks later to confirm

25
how do you dx vesicular stomatitis
serum, vesicular fluid, serology, virus isolation, rt-PCR
26
What is tx for vesicular stomatitis virus
1. Palliative- secondary infections 2. quarantine 14-30 day after last suspected case
27
why is there no commercial vaccine for vesicular stomatitis virus
makes dx difficult- hard to differentiate between infected vs vaccinated
28
how does vesicular stomatitis outbreak behave in norther vs southern climates
northern- rare outbreaks, more severe Southern- yearly cases, less severe
29
how is VSV transmitted and how does this help explain its cyclical appearance
culicoides midges which are only present seasonally. Often large parts of country are exposed and develop herd immunity for 5+years
30
what procedures must be taken when VSV is suspected and where are samples sent for dx
notify state/regional USDA vet. Samples sent to USDA labs in either Iowa or plum island