CNS Viruses (Exam 5) Flashcards
Rabies Virus is a ______-preventable disease.
vaccine
(T/F) Rabies Virus is highly contagious.
False
Mass canine vaccination programs allow for ________ _______ of Rabies Virus.
herd immunity
Fill-in the following for Rabies Virus:
Family: _________
Genus: _________
Rhabdoviridae
Lyssavirus
Rabies Virus is a (DNA/RNA) virus.
RNA
Lyssaviruses are broken down into ___ genotypes, Genotype __ being classical rabies while the others are various lyssaviruses in bats.
7
1
Diagnostic test that detects internal nucleocapsid proteins of Rabies Virus.
immunofluorescence
(T/F) Rabies can be transmitted from animal-to-animal or animal-to-human.
True
How is Rabies transmitted?
bite wounds (saliva into tissues)
In developed countries with vaccinated dogs, what hosts serve as the major cause of transmission to humans?
wildlife reservoirs
In less-developed countries, ______ and ______ serve as the primary reservoirs for Rabies Virus.
feral dogs
bats
________ serve as subclinical carriers of Rabies.
bats
(T/F) Clinical signs of Rabies usually show up at the time they become infectious.
True
(T/F) While rare, fomite transmission of Rabies Virus can occur.
False
(T/F) It is probably NOT possible to become infected by Rabies Virus via inhalation.
True
Match the type of animal to its characteristic in terms of Rabies Virus:
- antibodies w/o disease
- susceptible, CNS clinical disease
- maintenance hosts for transmission
- birds
- mammals
- wildlife
The two most important wildlife reservoirs for the spread of Rabies virus are:
skunks & bats
After a rabid animal bite, the infected saliva deposits deep into _______ where it replicates and binds at receptors of ________.
muscle
motor end plate
After rabies virus binds to the motor end plate receptors of muscle, it travels up the neuron and replicates in ______ and subsequently, peripheral nerves & organs, especially _______ where high titers of the virus occur.
brain
salivary glands
When Rabies Virus infects the limbic system, this is commonly called:
furious rabies
When Rabies Virus infects the neocortex, this is commonly called:
dumb rabies
(T/F) No particular clinical sign is pathognomonic for Rabies infection.
True
Rabies should always be a differential for neurologic disease is the animal is not ________.
vaccinated
The incubation period of Rabies Virus is determined by the _________ and _______ of the bite.
location & severity
Diagnosis of Rabies infection only occurs (ante/post)-mortem.
post
What diagnostic test is used on fresh brain tissue for Rabies diagnosis?
Direct Fluorescent Antibody Test
A positive Direct Fluorescent Antibody Test on fresh brain tissue is determined by the presence of _________ in neurons.
Negri bodies
(T/F) Rapid test kits are currently available for detect of Rabies Virus.
False
(T/F) Brains and heads intended for Rabies diagnosis should be frozen prior to testing.
False (can refrigerate)
______ impression smears and ______ biopsies can be used for antemortem Rabies diagnosis in humans.
corneal
skin
Regardless of vaccination status, if a dog, cat, or ferret bites someone, what is the protocol?
confine/observe for 10 days (evaluate by vet if develop signs)
Post-bite in a human, what helps to inactivate and lower the viral dose of Rabies?
irrigate/wash wound (soap & water)
(T/F) All Rabies vaccines are inactivated or vectored MLV. There are NO MLV vaccines licensed.
True
(T/F) There are few approved vaccines for wildlife kept as pets or wild animal hybrids.
False (NONE)
Which 4 species should always be vaccinated for Rabies?
dogs, cats, ferrets, horses
_______ are small, proteinaceous infectious particles that resist inactivation by procedures that modify nucleic acids.
prions
______ is the normal prion protein while ______ is the pathogenic prion variant causing misfolding.
PrPc
PrPsc
PrPc is degraded by ________ while PrPsc is resistant.
proteinase K
PrPsc is resistant to what 3 things other than proteinase K?
boiling, formaldehyde, irradiation
List the 3 major animal prion diseases discussed.
- Scrapie
- Chronic Wasting Disease
- Bovine Spongiform Encephalopathy
Which two species are affected by Scrapie?
sheep, goats
(T/F) Scrapie can be transmitted to humans.
False (not known to be zoonotic)
______ factors and strain ______ determine which animals are infected with Scrapie.
genetic
variants
How is Scrapie transmitted? (2 ways)
- oral route
- wounds from infected material
(T/F) The natural route of Scrapie transmission has NOT been proven.
True
List 3 clinical signs of Scrapie.
- ataxia
- pruritis (“scraping”)
- wasting
Scrapie has a (long/short) incubation period.
long
(T/F) Prion Disease, such as Scrapie, cause an immune response in the host.
False
After prions are ingested, they move to the lymphoid tissues and CNS, where they cause:
neuronal degeneration
All methods of Scrapie diagnosis require _______ and ______ reactions.
infected tissue
antibody reactions
Which 2 tests can be used to detect Scrapie?
IHC & ELISA
Which test is considered the “gold standard” for Scrapie diagnosis?
IHC
What kind of animals are affected by Chronic Wasting Disease?
mule deer, white-tailed deer, elk
(cervids)
The main clinical sign of Chronic Wasting Disease is chronic _________ which progressively leads to death, often due to __________.
weight loss
aspiration pneumonia
(T/F) The relationship between Chronic Wasting Disease and other spongiform encephalopathies is unknown.
True
(T/F) Chronic Wasting Disease is NOT present in Missouri.
False
Which two ways is Chronic Wasting Disease transmitted?
- direct contact (ingestion)
- indirect (environmental)
In terms of the indirect environment contamination route of CWD transmission, _________ is a major factor which determines prion persistence in the environment.
soil type
Chronic Wasting Disease has been experimentally transmitted to _______ and _______ via intracerebral inoculation or fed infected tissues.
ruminants
monkeys
(T/F) There is strong evidence for CWD transmitted naturally in humans.
False (not currently known)
Chronic Wasting Disease usually occurs in (young/adult) animals and is (never/sometimes/always) progressive and fatal.
adult
always
The “gold standard” for CWD diagnosis is immunohistochemistry of ______ or _____ tissues on necropsy.
brain
lymphoid
What disease is a reportable, chronic, degenerative disease affecting CNS of adult cattle caused by misfolded prions?
Bovine Spongiform Encephalopathy
Bovids infected with BSE begin agitated, anxious, and apprehensive but progress to:
abnormal gait & frenzied movements
BSE has a long incubation period of:
2-8 years
The most important route for BSE transmission is:
ingestion (feed containing infected meat & bone meal)
(T/F) BSE can be transmitted to humans.
True
BSE transmitted to humans is called:
Creutzfeld-Jakob Disease
In addition to bovids and humans, what other animals are known to develop BSE after being fed infected meat?
zoo cats
In BSE, prions are concentrated in what 3 regions?
eyes
brain
spinal cord
(T/F) BSE infected prions have been found in meat and milk of infected bovids.
False
(T/F) There are NO gross lesions for Bovine Spongiform Encephalopathy.
True
There are no ________ tests for BSE.
serological
The initial screening for BSE uses ________ test while confirmation uses scrapie-associated fibril-enriched ___________.
ELISA
Western Blot
