3. Rabies

All ________ are believed to be susceptible.

mammals

What wild terrestrial carnivores are the most commonly infected? What should be done with all these bites?

raccoons, skunks, and foxes; should be considered exposures unless tested negative

What other wild animal is not considered a reservoir for rabies? Why?

rodents; nerves from the CNS are very short so death is rapid and the rodents usually will not survive the the infecting bite

________ (________, ________) are rarely infected and have not been known to transmit rabies to humans.

lagomorphs; rabbits; hares

True or false: The US has been declared free of canine rabies virus variant transmission but this does not mean you still cannot get rabies from a dog.

true

Since 2000, more ________ than ________ are diagnosed with rabies.

cats; dogs

What is the most common wildlife to be carrying rabies along the eastern seaboard?

raccoon

What is the most common wildlife to be carrying rabies in middle America from Mexico to Canada?

skunk

What is the most common wildlife to be carrying rabies in alaska?

fox

What is the most common wildlife to be carrying rabies in hawaii?

mongoose

When do dogs, cats, and ferrets shed the virus for?

a few days prior to and during clinical signs

The incubation period is ________ ________.

highly variable

What is the incubation period in domestic animals?

3-12 weeks

What length incubation periods have been reported in humans?

greater than 1 year

How long do dogs usually shed rabies for in their saliva before clinical signs develop?

5-10 days

How long is the latent period?

up to 6 months

How long is the incubation period?

5-10 days longe than latent period

How long is required for the infection to become apparent?

several weeks

How is rabies transmitted?

bite or scratch

Where does replication occur?

in muscle and connective tissues at the site of inoculation

Where does it enter the peripheral nervous system?

neuromuscular junction

How does it spread?

up the peripheral nerves at the central nervous system

Where does the virus grow in high titers?

in the salivary glands

What appears in the neuron bodies?

negri bodies

What is the clinical spectrum?

P
A
C

• prodrome

• acute neurologic phase

• coma

What symptoms are part of the prodrome phase?

N
H
F
S
P

• nausea

• headaches

• fever

• sore throat

• photophobia

What symptoms are part of the acute neurologic phase?

A
N
H
B
S
P
H
P

• apprehension

• nervousness

• hallucinations

• behavioral anomalies

• salivation

• perspiration

• hydrophobia

• photophobia

What occurs during the coma phase?

S
D

• seizures

• death

True or false: The clinical presentation of rabies in animals is highly variable. These can range from inappetance, dysphagia, cranial nerve deficits, abnormal behavior, ataxia, paralysis, altered vocalization, and seizures.

true

Case definition requires a lab confirmation by what?

P
I

• positive direct fluorescent antibody test

• isolation of rabies virus (cell culture or lab animal)

Progression to death is ________.

rapid

True or false: There is no effective rabies antiviral drugs.

true

What are the two major categories of animal-to-human exposures?

bite and non-bite

category in which there is any penetration of the skin by teeth

bite

category that includes surgical recipients of corneas, solid organs, and vascular tissue, people exposed to large amounts of aerosolized virus, and contact of open wounds with saliva from a rabid animal

non-bite

What type of contact does not constitute rabies exposure? What are examples of this?

indirect; petting or handling an animal, contact with blood, urine, or feces, and contact of saliva with intact skin

Which two categories constitutes a true rabies exposure?

bite and non-bite

True or false: Bat exposures deserve special consideration. Any direct contact (especially children) with a bat.

true

How many organ transplantations have resulted in rabies cases?

16

What is the one type of human-human exposure that is known?

organ transplantation

True or false: Caring for a human rabies patient is not an exposure, unless a bite or saliva into an open wound occurred.

true

How many vaccines are licensed for human use in the US?

2

What are the vaccines licensed for human use in the US?

H
P

• human diploid cell vaccine (HDCV)

• purified chick embryo cell vaccine (PCECV)

What type of immunity do the vaccines stimulate?

active

When do the vaccines stimulate antibody response? How long do neutralizing antibodies persist?

7-10 days; several years

What type of immunity does the rabies immune globulin (RIG)?

passive

How long does the rabies immune globulin (RIG) provide immunity for?

~21 days

True or false: If you give the rabies vaccine and RIG at the same time, it will cause an immunologic battle.

true

What is the pre-exposure prevention protocol?

two doses of rabies vaccines at days 0 and 7

What is the follow-up for pre-exposure prevention?

serologic testing to ensure protection 1-3 years later or booster after 3 years without titer testing

What groups are considered high risk and and should have the pre-exposure prevention?

V
A
R
C

• veterinarians and staff

• animal handlers

• rabies researchers

• certain lab workers

What is the post-exposure prophylaxis in humans? What is this considered?

• wound treatment

• local infiltration of RIG

• vaccination

uniformly protective against rabies

What is the post-exposure regimen for humans not previously vaccinated?

• thorough wound cleansing with soap and water

• RIG (half at bite site and other half IM) concurrent with the 1st dose of vaccine

• four doses of vaccine at days 0, 3, 7, and 14 post-exposure

What is the post-exposure regimen for humans previously vaccinated?

• thorough wound cleansing

• vaccine on days 0 and 3

True or false: Post-exposure prophylaxis is considered a medical urgency, not emergency.

true

Approximately how many people receive post-exposure prophylaxis each year in the US? How many per year worldwide?

16,000-39,000; 10-12 million

More than how many people die from rabies in China each month?

200

True or false: Pre-exposure prophylaxis alone, however, may not be sufficient to protect without post-exposure prophylaxis.

true

True or false: The costs of post-exposure rabies prophylaxis can be significant.

true

What are the NASPHV recommendations for domestic animals?

A
R

• all dogs, cats, and ferrets should be vaccinated

• remove strays and unwanted animals (impound for 3 days in case of ownership or potential exposure)

What is very difficult for rabies in wildlife? Why?

control; there is no licensed parenteral rabies vaccines for use in wild animals or wild hybrids and states are encouraged to enact laws to prohibit importation, distribution, translocation, and private ownership of raccoons, skunks, coyotes, foxes, bats, and other wild species

Where are all USDA-licensed vaccines listed?

NASPHV compendium

There is no value in more frequent ________ than labeled.

vaccination

Adverse events are ________ in animals.

rare

What are examples of adverse events in animals? What should be done if these occur?

vomiting, injection site swelling, and lethargy; should be reported to USDA/APHIS/CVB

True or false: Zoos may vaccinate to protect valuable animals, but this does not affect post-exposure guidelines. Private practitioners do not have this latitude for wild or wild hybrid pets.

true

Human contact with what type of animal rabies vaccine does not constitute a rabies exposure?

injectable

Human contact with what type of animal rabies vaccine should be reported to the health department but is still not a rabies exposure?

vaccinia-vectored oral

True or false: Wild animals or hybrids should not be kept as pets, as there is no licensed, individual vaccines that exist for these species.

true

Who typically gives the vaccinations?

licensed DVM with approved vaccine

When are animals considered immunized?

28 days post initial vaccination

Regardless of the age at initial vaccination, when should the animal be boostered?

in one year

What is the typical vaccination schedule for dogs, cats, and ferrets?

initial vaccination at 3 months of age, booster one year later regardless of initial vaccine type, and booster every 3 years

What is considered for mass vaccination for carnivores in select situations? What is it labeled for use only in?

oral rabies vaccines (ORV); raccoons and coyotes

True or false: Rabid bats have been reported from all 48 contiguous states, with 1,704 in 2015 alone. This caused at least 43 human deaths in the USA. Reducing the bat populations is neither feasible nor desirable.

true

What should wild mammalian carnivores and bats that are unavailable for testing be considered?

rabid

What should occur that any unvaccinated dogs, cats, and ferrets that are exposed to a rabid animal? What if the client is unwilling to do that?

should be euthanized immediately; immediately vaccinate and place in strict isolation for 4 months for cats and dogs and 6 months for ferrets

What should happen to dogs, cats, and ferrets that have been exposed to a rabid animal and are current on vaccines?

re-vaccinated immediately and observed by owner for 45 days

What should happen to dogs, cats, and ferrets that have been exposed to a rabid animal and are overdue for booster with documentation? What are the other options?

boostered immediately and kept under owner control for 45 days; euthanasia or revaccination and strict isolation for 4 or 6 months

True or false: Any illness in an exposed animal should be reported immediately to the health department and if any signs suggestive of rabies develop, the animal should be euthanized and tested.

true

What type of livestock are the most frequently infected?

cattle and horses

What should be done with unvaccinated livestock? What if the client is unwilling?

should be euthanized immediately; confine and observe for 6 months on a case by case basis

What should be done with livestock that are current on vaccines?

should be revaccinated and observed for 45 days

What type of exposures are uncommon in a herd? Therefore, what is not warranted?

multiple exposures; herd restriction/quarantine is not warranted

What else can be done with an exposed animal? How long is commercial slaughter prohibited for post-exposure?

can be immediately custom-slaughtered; 8 months

What can inactivate rabies?

cooking and pasteurization

True or false: Drinking pasteurized milk or eating cooked meat does not constitute a rabies exposure. Although milk of rabid cow is theoretically transmissible, it is highly unlikely. The CDC has collected milk from rabid cows for 15 years and was unable to detect antigen or nucleic acids.

true

True or false: All other mammals exposed to a rabid animal should be immediately euthanized.

true

What is done for dogs, cats, and ferrets that have bit a human? Regardless of what? What should not be done during this period? What should be done if signs suggestive of rabies develop?

confined and observed for 10 days; vaccination status; do not vaccinate; euthanize and test immediately

What should be done with strays or unwanted animals that have bit a human?

should be euthanized and tested immediately

True or false: Other animals are evaluated on a case-by-case basis, off of species, circumstances of exposure, rabies, epidemiology, and exposing animal’s health/history.

true

When is testing for rabies in animals done?

for those animals that are potentially exposing humans or domestic animals

For all animals except bats, what part of the animal should only be submitted to the diagnostic laboratory? How should they be sent? How should they not be sent?

only the head or brain, including the brain stem; refrigerated; not frozen or chemically fixed

True or false: There are no USDA-licensed rapid test kits for commercially available antemortem diagnosis.

true

What testing is used on the submitted brain tissue?

PCR assay

What are the advantages of PCR assay?

E
G
A
M

• easier, quicker, and less expensive than DFA test

• greater sensitivity and specificity than the DFA test

• accurate even on deteriorated tissue

• more likely to be used in lesser-developed areas where rabies is much more prevalent

What is being considered by WHO and OIE as the first degree rabies test?

PCR assay

Who regulates the importation of dogs and cats into the US?

the CDC

Prior to interstate movement for cats, dogs, ferrets, and horses, what do they need to have?

current rabies vaccination and current, valid rabies vaccination certificate (NASPHV Form 51)