Rabies

1
Rabies
2
Rabies

• Kendra McQueen
• Jennifer Rasmussen
• Edward Guevara

3
Description

• Rabies is an infectious disease caused by the
  Lyssavirus of the Rhabdovirdae family that
  attacks the nervous system. These are the only
  known viruses to travel along the nerves after
  infection. The virus is usually in the saliva of
  a rabid animal and the route of transmission is
  nearly always by a bite. By causing the infected
  animal to be exceptionally aggressive, the virus
  ensures its transmission to the next host.
  Transmission through the mucous membranes has
  occurred by people exploring caves populated by
  rabid bats.
• After a bite the virus enters the body and
  starts to replicate before it moves to the
  peripheral nerves. It moves slowly in the nervous
  tissue jumping from nerve cell to nerve cell
  where it eventually reaches the CNS. At the
  brain it causes encephalitis and the typical
  symptoms of rabies appear. The incubation period
  for rabies is the time it takes to get from bite
  to brain which can be anywhere from 2 weeks to
  several, months. Bites on the hand and face can
  move much quicker to the CNS because of the many
  nerve endings found at these sites. As soon as
  the virus gets to the brain it travels to the
  salivary glands, replicates in abundance and is
  shed in the saliva. At this point the animal
  becomes infectious and can transmit the disease
  through a bite.

4
Structure

• The Rabies virion is bullet shaped and contains a
  non-segmented, negative stranded RNA genome that
  encodes five proteins. It is approximately 180nm
  long and 75nm wide. Its RNA measures at 3000nm.
  
• The RNA is encased by nucleoprotein, which is
  covered by the ribonucleoprotein (RNP) helical
  core. Phosphoprotein and polymerase are
  associated with the RNP. A matrix protein covers
  the RNP and is surrounded by an envelope.
• The surface of the envelope is covered by around
  400 spike-like glycoprotein10nm long.

5
(No Transcript)
6
Replication

• Attachment the virus attaches to the nerve cell.
• Penetration the virus enters the cell
• Uncoating the envelope is removed.
• Transcription and translation the virus
  replicates.
• Budding the new virus leaves the host cell and
  attaches to other nerve cells and spreads from
  brain to the rest of the body by the nerves.

7
Rabies in humans

• The incubation periodthe time from exposure to
  the rabies virus until symptoms appearis usually
  4 to 6 weeks. In rare cases, the incubation
  period can last from several days to more than a
  year after exposure to the virus.
• If you are concerned that you may have been
  exposed to the rabies virus, it is important to
  seek medical attention before symptoms develop.
  Rabies is nearly always fatal if not treated
  before the appearance of symptoms.

8
Signs and Symptoms
Pain at bite site Fever Malaise
Fatigue Anorexia Hydrophobia
Inability to Swallow Cough Nausea
Vomiting Sore Throat Muscle pain
Headache Nuchal Rigidity Neurological Changes
CNS Damage Hallucinations Seizures
Alt Consciousness Lethargy Coma
Death
9
Is rabies a common disease?

• In the United States in 2001, there were 7,437
  cases of rabies reported in animals. Most were in
  wild animals.  One case was reported in a human.
    Rabies occurs in almost every state. Hawaii is
  the only state that has not had a single native 
  case of rabies in animals or humans. As you can
  see by this map, rabies is most common in the
  eastern United States.

10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
Rabies Diagnosis dFA Test
14
Rabies Diagnosis dFA Test
15
Prevention

• Rabies is preventable!
• Be a responsible pet owner
• Keep vaccinations up-to-date for all dogs, cats
  and ferrets. This requirement is important not
  only to keep your pets from getting rabies, but
  also to provide a barrier of protection to you,
  if your animal is bitten by a rabid wild animal.
• Keep your pets under direct supervision so they
  do not come in contact with wild animals. If
  your pet is bitten by a wild animal, seek
  veterinary assistance for the animal immediately.
  
• Call your local animal control agency to remove
  any stray animals from your neighborhood. They
  may be unvaccinated and could be infected by the
  disease.
• Spay or neuter your pets to help reduce the
  number of unwanted pets that may not be properly
  cared for or regularly vaccinated.

16
Prevention

• Avoid direct contact with unfamiliar animals
• Enjoy wild animals (raccoons, skunks, foxes) from
  afar. Do not handle, feed, or unintentionally
  attract wild animals with open garbage cans or
  litter.
• Never adopt wild animals or bring them into your
  home. Do not try to nurse sick animals to
  health. Call animal control or an animal rescue
  agency for assistance.
• Teach children never to handle unfamiliar
  animals, wild or domestic, even if they appear
  friendly. "Love your own, leave other animals
  alone" is a good principle for children to learn.
  
• Prevent bats from entering living quarters or
  occupied spaces in homes, churches, schools, and
  other similar areas, where they might come in
  contact with people and pets.

17
Prevention

• When traveling abroad, avoid direct contact with
  wild animals and be especially careful around
  dogs in developing countries. Rabies is common
  in developing countries in Asia, Africa, and
  Latin America where dogs are the major reservoir
  of rabies. Tens of thousands of people die of
  rabies each year in these countries. Before
  traveling abroad, consult with a health care
  provider, travel clinic, or your health
  department about the risk of exposure to rabies,
  pre-exposure prophylaxis, and how you should
  handle an exposure, should it arise.
• Pre-exposure vaccinations are intended for high
  risk people, such as veterinarians, lab workers,
  animal handlers, wildlife officers, those who are
  in contact with rabid bats, skunks, raccoons,
  cats, dogs or other species at risk of having
  rabies and international traveler.
• Note people at high risk should have a blood
  sample tested every six months and receive a
  booster vaccine (when necessary), in addition to
  a pre-exposure vaccine.

18
Treatment

• There is no treatment for rabies after symptoms
  of the disease appear. However, two decades ago
  scientists developed an extremely effective new
  rabies vaccine regimen that provides immunity to
  rabies when administered after an exposure
  (post-exposure prophylaxis) or for protection
  before an exposure occurs (preexposure
  prophylaxis). Although rabies among humans is
  rare in the United States, every year an
  estimated 18,000 people receive rabies
  preexposure prophylaxis and an additional 40,000
  receive post-exposure prophylaxis.

19
Treatment Preexposure prophylaxis

• Preexposure vaccination is recommended for
  persons in high-risk groups, such as
  veterinarians, animal handlers, and certain
  laboratory workers. Other persons whose
  activities bring them into frequent contact with
  rabies virus or potentially rabid bats, raccoons,
  skunks, cats, dogs, or other species at risk of
  having rabies should also be considered for
  preexposure prophylaxis. In addition,
  international travelers likely to come in contact
  with animals in areas of enzootic dog rabies
  which lack immediate access to appropriate
  medical care, including biologics, should be
  considered for preexposure prophylaxis.

20
TreatmentPost-exposure prophylaxis

• Post-exposure prophylaxis (PEP) is indicated for
  persons possibly exposed to a rabid animal.
  Possible exposures include animal bites,  or
  mucous membrane contamination with infectious
  tissue, such as saliva. For more information on
  types of exposures, PEP should begin as soon as
  possible after an exposure. There have been no
  vaccine failures in the United States (i.e.
  someone developed rabies) when PEP was given
  promptly and appropriately after an exposure.
• Administration of rabies PEP is a medical
  urgency, not a medical emergency. Physicians
  should evaluate each possible exposure to rabies
  and as necessary consult with local or state
  public health officials regarding the need for
  rabies prophylaxis.
• In the United States, PEP consists of a regimen
  of one dose of immune globulin and five doses of
  rabies vaccine over a 28-day period. Rabies
  immune globulin and the first dose of rabies
  vaccine should be given as soon as possible after
  exposure. Additional doses of rabies vaccine
  should be given on days 3, 7, 14, and 28 after
  the first vaccination. Current vaccines are
  relatively painless and are given in your arm,
  like a flu or tetanus vaccine.

21
TreatmentSummary

• No treatment for rabies after symptoms of disease
  appear.
• Quarantine and/or vaccination to eradiate
  disease.
• Wash wound with a special substance containing
  anti-rabies serum and water.
• Get a post-exposure prophylaxis injection of
  HRIG, human rabies immune globulin.
• Follow up with the recommended subsequent
  treatment, which is to receive five. injections
  of HDCV, human diploid cell vaccine.
• Sometimes Hyper-immune serum globulin is used in
  addition.
• Note Immediate treatment after exposure is
  important, as well as, maintaining post-exposure
  prophylaxis.

22
Sources

• Images
• http//www.vet.ksu.edu/depts/rabies/images/rabstru
  c.jpg
• http//www.visualsunlimited.com/results.jsp
• http//www.cdc.gov/ncidod/dvrd/kidsrabies/Statisti
  cs/stats.htm
• CDC
• http//www.cdc.gov/ncidod/dvrd/rabies/
• Yahoo Health
• http//health.yahoo.com/ency/healthwise/hw181108_
  yltAmvLeHDlbgVyLgmqnogs2J0Su7cF
• Textbook