Rhabdoviridae

Question 1

Rabies
enveloped or non-enveloped
shape
linear or circular
+/- ds or ss RNA
sensitvity
stability

Answer 1

enveloped, helical capsid
“bullet shaped”
linear -ssRNA
thermolabile, sensitive to UV/sun and detergent disinfectants
stable in coo, moist environments w/ basic pH

Question 2

Rabies
reservoirs
zoonotic?
reportable?

Answer 2

dogs, jackals, mongoose, bats, wolves, chinese ferret badgers, foxes, skunk, raccoon
ZOONOTIC
REPORTABLE

Question 3

Rabies
incubation period
what does it depend on?
dogs?
humans?
horses?

Answer 3

depends on location of bite relative to the brain (bite on head/neck shorted IP than limb) & amount of virus in saliva
dogs 2 wk-3mo
human 3wk-2mo (up to 7yr)
horse 2-6wk

Question 4

Rabies
Pathogenesis

Answer 4

replicates in SQ tissue/myocytes
glycoprotein G binds to nACH R on nerve endings
transported within axons
infects nerves in limbic system
transferred via nerves from brain to salivary glands and other organs
replicates in salivary glands and shed into salvia within 2-7 days

Question 5

Rabies
transmission (5)

Answer 5

saliva or neural tissue
bite most natural/successful way
mucous membrane exposure of eyes, nose, mouth or organ transplant
bats (flying vector)

Question 6

most human rabies is acquired via _______

who are more at risk?

Answer 6

insectivorous bats

infants/young children and people with reduced mental function due to meds, alcohol, illness or age

Question 7

what type of replication strategy does rabies use?

where does it replicate?

_____ bodies
anti-______
highly ______
escapes ______ how?
_____ opposed to neural cell death
NO ______

Answer 7

self-limiting replication strategy

cytoplasm

intracytoplasmic eosinophillic inclusions “nregl bodies”
anti-apoptotic
highly neurotropic
escapes PNS by hiding in CNS behind BBB
neuronal dysfunction
NO viremia

Question 8

list the stages of rabies disease

Answer 8

1. incubation period (subclinical)
2. prodromal period (change in temperament, not observed)
3. furious rabies (neuro signs e.g. biting, hypersalivation)
4. paralytic
5. terminal (seizure, coma, resp failure)

Question 9

the difference in rabies clinical signs in small animals, ruminants, horses

Answer 9

small animals - fever, behavior, drooling, sensitive, incontinence, paralysis, biting, lameness
ruminants - colic, incontinence, bloat, death
horses - colic, aggressive, death

Question 10

rabies vaccine

Answer 10

whole virus G & N glycoproteins

Question 11

significance of G protein

Answer 11

neutralizing Ab to prevent CNS entry

Question 12

significance of N protein

Answer 12

T cell activation

Question 13

rabies titers
pet exports
complete neuralization
dog/cat min acceptable RVNA level

Answer 13

pet exports 0.5 IU/mL
complete neutralization at 1:5 serum dilution or 0.1 IU/mL
dogs 0.2 IU/mL
cats 0.1 IU/mL

Question 14

Rabies
treatment

Answer 14

medical urgency NOT emergency
depends on animal, type of exposure, avialability of biting animal for rabies testing/observation

wash wound, see Dr, test animal, contact local health department or animal control, post-exposure treatment, four IM vx over 28 days

Question 15

Rabies
Diagnostics

what type of tissue do you need?

Answer 15

direct fluorescent Ab of brainstem/cerebellum (test of choice)
PCR, IHC, histopath
can test whole carcass, head, brain, brainstem, cerebellum or hippocampus

FRESH tissue not formalyin fixed

Question 16

what is rabies sensitive to

Answer 16

dry heat >131 degrees
UV light/sunlight
disinfectants and detergents

Question 17

what does it mean for rabies to be neurotropic?

shedding is max where?

Answer 17

blood, milk, urine, feces NOT infectious
saliva/salivary glands/brain highly infectious
enervated organs considered for organ transplants
salivary glands have max shedding

Question 18

Rabies
quarantined periods
when do most animals shed virus in salvia for ____ days before behavior changes
animal asymptomatic beyond 10th day, what happens?
symptomatic or dies before 10th day, what happens?

Answer 18

10 days

4-5 days

beyond 10 days, not shedding at time of bite

before 10 days, test for rabies

Question 19

guidelines for symptomatic dogs or stray/unwanted animals?

Answer 19

euthanize and test

Question 20

guidelines for healthy owner or animal?

Answer 20

daily observation for 10 days
if signs appear within 10 days euthanize and test
vx not recommended during these 10 days to avoid confusion/adverse vx effects

Question 21

Vesicular Stomatitis Virus
hosts?
economic importance?
pathogenesis/clinical signs?
transmission?
reportable?
zoonotic?

Answer 21

wide host range - cattle, horses, humans, swine, deer, foxes, coyotes, rodents, insects, plants
loss of production, indistinguishable from foot and mouth
infects epithelial cells leading to vesicles –> ulcers on tongue, oral mucosa, teats, coronary bands
vector/cut abrasions - black flies, midges (Cuilocoides), mosquitos, houseflies, sand flies
zoonotic & reportable

Question 22

horse specific lesions due to VSV

Answer 22

ulcers on tongues/ears

Question 23

swine specific lesions due to VSV

Answer 23

ulcers on snout/coronary bands

Question 24

Name vesicular diseases of swine

Answer 24

vesicular stomatitis virus
vesicular exanthema of swine
foot and mouth disease virus
swine vesicular disease
seneca A virus

Question 25

Bovine Ephemeral Fever Virus
known as?
hosts?
disease?
economic impact?
transmission?
reportable?

Answer 25

“three day sickness or three-day fever”
cattle, yaks, water buffalo
acute febrile disease
impacts milk production
arthropods ( mosquitos/midges)
reportable

Question 26

Spring Viremia of Carp
hosts?
disease?
transmission?
reportable?

Answer 26

farmed carp
acute diseases, fatal in young, range from asymptomatic to hemorrhage of skin, gills, eyes, edema
shed skin/gill lesions, urine, feces, fomites, parasitic invertebrates