Danielle Flores & Bailey Brown Rabies. What is Rabies? Rabies is a preventable viral disease of warm...
Click here to load reader
prev
next
of 20
Danielle Flores & Bailey Brown Rabies. What is Rabies? Rabies is a preventable viral disease of warm blooded mammals most often transmitted through the
What is Rabies? Rabies is a preventable viral disease of warm
blooded mammals most often transmitted through the bite of a rabid
animal.
Slide 3
Etiology Rabies is caused by lyssaviruses in the Rhabdovirus
family The Rhabdoviruses are uniquely bullet-shaped. They contain a
negative stranded RNA genome and are very stable to drying.
Lyssaviruses are a group of viruses that includes rabies and bat
lyssavirus Lyssaviruses are usually confined to 1 major species in
a given area, although spillover to other species is common.
Slide 4
Rhabdovirus
Slide 5
Rabies History The disease was first documented by the ancient
Babylonians. Girolama Fracastoro discovered the rabies virus. Louis
Pasteur discovered the rabies vaccine in 1895, when he was 63 years
old, relying on Fracastoro's written notes. Rabies was so feared in
early history that many patients who suffered from the illness were
put to death, either intentionally or accidentally It was common
practice to shoot, poison, suffocate or use some other form to kill
any animal or human with the rabies virus.
Slide 6
Signalment Breed: Rabies most commonly affects carnivores and
bats, but can affect all mammals. Age: Young animals may be more
susceptible to rabies than older animals. Gender: It is unknown
whether the males or females are more susceptible to rabies.
Slide 7
Transmission Rabies is zoonotic (primarily through bats) Rabies
can infect all mammals through transmission in the saliva(dogs are
primary vectors) Most exposure results from animal bites When an
animal is bit, the virus ascends through the peripheral nerves to
the brain. Once it enters the brain, the virus replicates. It then
moves to the salivary glands. After the virus enters the salivary
glands, it may be transmitted to other animals or humans.
Slide 8
Clinical Phases The clinical course may be divided into 3
phases Prodromal Lasts 1-3 days Loss of appetite Lethargy
Intermittent fever irritability Excitative mad-dog phase Lasts less
than a week Sometimes skipped Lack of coordination, twitching,
and/or seizures Aggressive behavior Restlessness and roaming lack
of recognition for familiar people and places Lack of fear toward
natural predators paralytic/endstage Foaming at the mouth This
symptom is caused by the growing paralysis of the throat and jaw
muscle Slack jawed appearance Full body paralysis, which results in
death It should be noted that the virus can remain active inside a
dead animal for forty-eight hours
Slide 9
Clinical Signs Most animals will exhibit signs of disturbance
in the CNS, but signs vary with species. Common signs include:
progressive paralysis sudden anorexia apprehension or nervousness
Irritability Hyperexcitability Ataxia altered phonation changes in
temperament
Slide 10
Tests Humans: Fluorescent antibody test on punch biopsy of skin
from the nuchal region and corneal impressions In vitro virus
isolation from saliva Virus neutralization assay on serum, for
evidence of rabies antibody Virus neutralization assay on
cerebrospinal fluid, for evidence of rabies antibody rt-pcr (Real
Time-Polymerase Chain Reaction) for viral RNA and genomic
nucleotide sequence analysis on saliva Animals: Testing in animals
is most frequently done using the direct fluorescent antibody (DFA)
test. requires brain tissue from animals suspected of being rabid.
The test can only be performed post-mortem
Slide 11
Treatment No cure. if a person is bitten by a rabid animal and
has not yet experienced symptoms, there is an extremely effective
post-exposure treatment, which includes an injection of rabies
immune globulin and several containing rabies vaccine given over a
28-day period. Rabies vaccination (can be given before or after
infection) using a human diploid cell vaccine (HDC) or Purified
chick embryo cell vaccine (PCEC). Killed rabies vaccine is given at
12 weeks or older in dogs and cats.
Slide 12
Treatment Always wash and care for a wound, if bitten, with
soap and water as soon as possible. If your pet bites a person, it
must be quarantined for 10 days at your expense.
Slide 13
Prognosis Rabies is considered a fatal disease, with death
occurring three days to one week from the first sign of symptoms.
There are few, if any, reports of recovery from rabies.
Slide 14
Pathologic Lesions Histopathologic evidence of rabies
inflammation in brain tissue and meninges includes the following:
Mononuclear infiltration Perivascular cuffing of lymphocytes or
polymorphonuclear cells Lymphocytic foci Babes nodules consisting
of glial cells Negri bodies
Slide 15
Perivascular cuffing or inflammation around a blood vessel.
Perivascular inflammatory cell infiltrates in hematoxylin &
eosin stained brain tissue. (100x Magnification Babes Nodules
Slide 16
Negri body in infected neuron Enlargement of a Negri body in
Sellers stained brain tissue. Note the basophilic (dark blue
granules in the inclusion).
Slide 17
Prevention Avoid Wild Animals (&BATS!) Many bites and
scratches that necessitate post exposure therapy occur when people
try to feed or handle a wild animal. Vaccinate Domestic Animals
Approved rabies vaccines are currently available for dogs, cats,
ferrets, horses, cattle, and sheep. Pre-exposure Vaccination of
Humans Pre-exposure vaccination should be offered to all persons
whose activities place them at increased risk for being exposed to
the rabies virus or to potentially rabid animals. A. Prevent
contact with saliva of infected animals, B. Wash bite wounds and
apply providone-iodine solution; C. Vaccinate dogs and cats
Slide 18
Client Education Vaccinate pets Never handle wild animals that
appear tame Dont leave food outside The quarantine is to protect
humans, not your pet. We dont want rabies!
Slide 19
http://www.youtube.com/watch?v=JZj3C0MMQ VA
http://www.youtube.com/watch?v=JZj3C0MMQ VA
