Lecture 27: Rabies in Animals and Humans Flashcards
how many people die from rabies each year
60,000 (40% children)
what family is rabies from
rhabdoviridae
what are the wildlife reservoirs for rabies in U.S.
all warm blood mammals
raccoons, skunks, foxes, bats
are dogs and cats reservoirs for rabies
no!
outside the U.S. what is the primary rabies variant
canine rabies (making imported dogs an ongoing concern)
what did CDC put in place to protect U.S. from canine variant of rabies
2021: temporary import ban
when was canine specific rabies eradicated in U.S.
2007
how is rabies transmitted
direct contact with fresh saliva or brain/nervous system tissue
what are two major categories of direct contact transmission routes
bite or non-bite
what is a non-bite transmission route for rabies
contamination of open wounds with saliva from rabid animal
can indirect contact (i.e. petting or handling animal, contact with blood, urine feces, or saliva with intact skin) cause rabies
no!
between 2000-2020 what percent of human rabies infections were acquired from bat associated variants in U.S.
82%
any direct contact with a bat should be considered
potential exposure unless bat tested negative
how can rabies be transmitted from human to human
organ transplants
what does incubation period of rabies depend on
site of bite wound/inoculation, wound care, and previous vaccination/presence of antibodies
what is the range for incubation period for rabies in domestic animals
3-12 weeks
what is the pathogenesis of rabies
- virus inoculated
- viral replication in muscle
- virus binds nACHR’s at NMJ
- virus travels on axons in retrograde fashion
- replication spinal cord and rapid ascent to brain
- infection of brain neurons
- centrifugal spread along nerves to salivary glands, skin, cornea
what are the clinical signs of rabies in dog
aggression or unusual behavior, excessive salivation, choking or gagging, cranial nerve deficits, ataxia, paralysis, seizures
how would rabies present in a normally nocturnal animal
active during day or showing reduced fear of humans
what are the three stages of CNS infection
- prodromal
- excitative “furious rabies”
- paralytic “dumb rabies”
what is prodromal phase
1-3 day period characterized by behavioral changes
what is the excitative ohase
3-4 days of hyperactivity to external stimuli and bite anything near
what is the paralytic phase of rabies
damage to motor neurons causes incoordination/paralysis in hind end, drooling and difficult swallowing, death caused by respiratory arrest
how do you test for rabies
postmortem examination of brain via DFA
what are the prodromal clinical signs in humans for rabies
nausea, headache, fever, sore throat, photophobia
what are the acute neurological phase in humans
apprehension, nervousness, hallucinations, behavioral, anomalies, salivation, perspiration, hydrophobia, photophobia
what is CFR in humans for rabies
> 99% (survival has been documented in 14 cases)
what are some antemortem testing in humans for rabies
saliva, serum, spinal fluid, and skin biopsy at nape of neck
which species is required by AZ law to be vaccinated against rabies
rabies
what is required for cats and dogs to enter arizona
CVI
certificate proving vaccinated against rabies
when are animals considered immunized post rabies vaccine
28 days
when are boosted animals considered immunized post rabies vaccine
immediately
what is the typical vaccination schedule for rabies in dogs, cats, ferrets
initial vaccine at 3 months of age
booster one year later
booster every 3 years
what is a common injection site reaction in cats
sarcomas
where should you avoid injecting vaccines in cats
dorsal neck, high on hindleg, cranial to scapula/chest
where are recommended sites for injecting vaccines in cats
low on fore and hindlimbs or tail
what type of rabies vaccine is labeled use in raccoons and coyotes
oral rabies
what is the vaccine protocol for wolf dogs or wild cat/domestic cat hybrids
no approved parenteral vaccines exist in U.S.
use of licensed vaccines is considered off label
what is the protocol for a hybrid pet that has been exposed to rabies or bites a human
no established quarantine periods so immediate euthanasia and rabies testing required despite vaccination history
in arizona is a ribers titer recognized as an index of immunity
no!
what is the protocol for pre-exposure vaccine prevention for humans
two days of RV on day 0 and day 7
how often should serologic testing and booster be done
every 10 years and booster accordingly
what is the protocol for post-exposure prophylaxis in humans
wound treatment, local infiltration of RIG, vaccination
what is the post exposure protocol for those humans unvaccinated against rabies
thorough wound cleaning, RIG (half at bite site, half IM)
four doses of RV: day 0, 3, 7, and 144
what is the post exposure protocol for humans vaccinated against rabies
thorough wound cleaning, two doses of RV on days 0 and 3
post-exposure prophylaxis is considered a medical ___ not ___
urgency not emergency
where should questions regarding possible rabies exposure to pet be directed
state or local public health authorities
what animals are not suitable for rabies testing and should be regarded as rabid
wild mammalian carnivores, skunks and bats
what protocol was established in texas for post exposure prophylaxis
no USDA licensed biologics but in texas PEP prevent 100% of deaths with vaccination within 96 hours, booster at 3 and 8 weeks and strict quarantine for 90 days
which state specifically allows for PEP in animals
texas
what is protocol for currently vaccinated animal exposed to rabid animal
revaccinate immediately and keep under owner control and observation for 45 days
what is protocol for currently unvaccinated animals exposed to rabid animal
euthanize immediately, if owner unwilling immediately vaccinate and place in strict quarantine at owners expense for 4-6 months
what is protocol for animals overdue for booster WITH documentation but have been exposed to rabid animal
booster immediately and keep under control and observation for 45 days
what is protocol for animals overdue for booster WITHOUT documentation
treats as unvaccinated or prospective serologic monitoring
what does prospective serologic monitoring entail
day 0: collect blood before booster, booster and put animal into strict quarantine
day 5: collect blood sample for titer (> 0.5IU/mL)
adequate response: considered vaccinated and put in 45 day observation
inadequate response: considered unvaccinated and put into 6 month strict quarantine
unvaccinated livestock exposed to rabies should be…
euthanized immediately
vaccinated livestock exposed to rabies should be
revaccinated and observed for 45 days
how long is commercial slaughter prohibited in exposed animal
8 months
does cooking and pasteurization inactivate rabies virus
yes!
what is protocol for owned dogs, cats and ferrets who bite humans
confirmed and observed for 10 days, regardless of vaccination status, do not vaccinate during this time period
if no signs, no rabies exposure
if clinical signs, euthanize and test immediately
what is protocol for strays or unwanted animals that bite humans
should be euthanized and tested immediately
