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It causes acute encephalitis (inflammation of the brain) in mammals, mostly fatal in non-vaccinated humans
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Bites
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Sneezes
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Kisses
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Transplant surgery (it is very rare but it happened once)
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Receive vaccination
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Wear protective materials when handling anything from suspected rabid animal(s)
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Disinfect/sterilize areas that may be contaminated with the rabies virus
- In order to cause an infection, the rabies virus enters the body and reaches nerve cells.
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First 2 to 12 weeks (possible to be as long as 2 months): flu-like symptoms
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Soon after: partial paralysis, brain dysfunction, anxiety, insomnia, confusion, unusual behavior, uncontrolled mental problems
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Later Stages: large production of saliva and tears, unable to speak and swallow, shows panic when presented liquids, thirsty
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The body is not able to defend itself if it is not vaccinated.
1. This treatment is highly successful if it is performed within 14 days after infection
Steps:
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Wash the wound with soap and water
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Inject 1 dose of immunoglobulin in the region of bite and muscles around the bite (Vaccinated patients do not receive immunoglobulin)
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Total of 5 doses of rabies vaccine are given over a 28 day period
2. Vaccine: is administered as an injection of killed rabies virus
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Total of 3 injections are need: the first two with interval of one week, and the last one three weeks later
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Provides protection of 3 years
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21 people have died in Canada from rabies since 1925.
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Rabies is an occupational risk for people who work with wild animals, livestock, or pets. (Ex. Hunters, veterinarians, meat packers, wildlife biologists, laboratory animal researchers and technicians, etc.)
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"Love your own, leave other animals alone” is a principle for children to learn to prevent them from handling unfamiliar animals.
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According to the Canadian federal regulations, all suspected rabid animals must be reported without delay to the local district office of Animal Health Department of the Canadian Food Inspection Agency.
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An annual cost of $300 million to associate with rabies detection, prevention, and control in the US is estimated.
by Tiffany Chen
Block C
RABIES
1. Virus name (scientific)
Lyssavirus rabies virus
2. Disease/disorder caused by virus
Ø Causes inflammation of the brain in mammals
Ø Causes paralysis
3. Description of virus structure
Ø Single-stranded, neurotropic (tending to attack the nervous system) virus
Ø Encodes 5 proteins
Ø Averages approximately 780nm in length
Ø Mature virus has bullet shape, a protein coat, and lipid envelope
Ø One end is rounded, while other end is concave
Ø Saliva of a rabid animal, usually from a bite
Ø Spread between humans by transplant surgery (cornea transplants)
5. How can transmission be prevented?
Ø Never touch unfamiliar, wild animals
Ø Never adopt wild animals or bring them home
Ø Do not nurse sick animals back to health
Ø Check the donor for possible signs of rabies
Ø Vaccination
6. Describe the type of body cells attacked.
Ø Nerve cells (brain and spinal chord)
Ø Once inside the body, the virus travels along the nerves that run throughout the body.
Ø Main target is the brain
7. What are the symptoms of infection?
Ø Symptoms usually occur 30-90 days after bite/infected
Ø Once symptoms develop, it results as death
Ø Fever, headache, sore throat, feeling tired
Ø Pain/tingling at the site of bite
Ø As virus gets to brain, person may act nervous, confused, upset
Ø Hallucinations and hydrophobia develop
Ø As disease advances person is paralyzed, enters coma, and dies
8. How does the body defend itself?
Ø Body can not defend itself without vaccination
Ø Can learn to defend after vaccine is injected into body
9. Are there any treatments/vaccines? If so, describe
Treatment:
Ø
Ø 1 dose of immunoglobulin is injected in the region of the bite as well as the muscles surrounding it.
Vaccination
Ø These are anti-rabies shots
Ø These shots produce an immune response
Ø Three injections are shot: the first two in one week and the last one three weeks later
10. Five Interesting Facts
Ø Each year, it kills more than 50,000 people and millions of animals around the world
Ø Raccoons are the most common wild animals with rabies today
Ø It naturally only affects mammals
Ø One prevention activity is the oral vaccine program:
à Oral vaccines in bait are dropped from airplanes to areas where wildlife are likely to be
à Animals eat the food with the vaccine inside it
RABIES
Scientific Name…
Lyssavirus Rabies virus
Disease and disorder caused by Rabies…
Rabies causes paralysis, cerebral dysfunction, anxiety, insomnia, confusion, agitation, abnormal behaviour, paranoia, hallucinations which progress to delirium. It also causes the production of large quantities of saliva and tears that progress to the inability to speak or swallow. This can result in ‘hydrophobia’ where the victim finds difficulty in swallowing; shows panic when presented with liquids to drink; and cannot quench their thirst. Death is almost inevitable when one is diseased with Rabies.
Rabies is transmitted…
The rabies virus infects the body usually through a bite from a rabid animal. The virus is usually present in the nerves and saliva of the animal. Transmission can also occur via the air through mucous membranes; transmission in such form may have happened in people exploring caves populated by rabid bats. Transmission between human is extremely rare but it can happen through transplant surgery.
Preventive measures against rabies…
- The first and most valuable preventive measure is through cleaning of the wound with soap and water, and immediate medical attention.
- Never touch unfamiliar or wild animals.
- Never adopt wild animals or bring them into your home.
- Avoid direct contact with stray animals as they are not likely to have been vaccinated against rabies.
- Secure trash cans and pet foods to avoid attracting wild animals.
- Walk dogs on a leash. Never allow them to roam freely in the wildlife.
- Call the animal control officer to take wild or stray animals away, especially if the animal is acting strangely.
- If your pet is bitten, get a rabies booster vaccination for the animal.
- Make sure your pet get and wears a rabies vaccination tag.
- Keep pets in a fenced yard or on a leash.
- Workers such as veterinarians, animal control officers should be immunized to ensure they have protection before having any contact with any animal.
- Workers that are comparatively less likely to encounter rabid animals should be educated on the risks and training on protection if they encounter an animal with rabies.
Which cells does rabies attack…
The target of the rabies virus is nerve cells. Nerve cells are part of our body’s nervous system. The nervous system helps direct body movement and adjusts to changes going on in our bodies. As the virus is inside our body, it immediately travels along the peripheral nerves that run throughout our body. Its main target is the brain and spinal cord.
There are 4 main stages of how rabies virus interacts with nerve cells:
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1. |
Attachment |
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The rabies virus attaches to a healthy nerve cell. |
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2. |
Penetration |
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The cell takes in the virus. |
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3. |
Replication |
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The virus multiplies rapidly inside the cell |
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4. |
Budding |
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The new rabies virus leaves the host cell. It continues to attach to other nerves cells. The virus spreads from the brain to the rest of the body. |
Rabies’ Symptoms…
It usually takes rabid animals 20 to 60 days after exposure to develop the symptoms. Symptoms include the rabid animals becoming very aggressive, combative, and highly sensitive to touch and other stimulations. This is the ‘furious’ from of rabid animals. There is also the ‘dumb’ form of rabid animals in which the animal is lethargic, weak in limbs, and unable to raise head or make sounds because its throat and neck muscles are paralyzed. Either way, death occurs a few days after symptoms appear, usually due to respiratory failure.
As for humans, the course is similar. After a symptom- free period of 10 days to a year or more, the patient will suffer from discomfort, feeling faint (Malaise), loss of appetite, fatigue, headache and fever. Patients may also suffer from pain which may be itchy or numbness at the site of exposure, they may complain of insomnia or depression. 2 to 10 days later, the signs of nervous system damage appear. Hyperactivity, hypersensitivity, hallucinations, seizures, and paralysis are all symptoms of rabies’ victims. Death may be sudden due to cardiac or respiratory system failure.
The body protects itself against rabies by…
The body produces antibodies to protect itself against the disease. Antibodies contribute to immunity in 3 main ways: the can prevent infectious agent from entering or damaging cells by binding them; they can stimulate the removal of an infectious agent by macrophages and other cells by coating the pathogen; and they can trigger direct pathogen destruction by stimulating other immune responses.
Treatments and vaccines for rabies…
There is no successful treatment for rabies once the disease has progressed to the point where symptoms appear. Medical treatment may extend life but the disease eventually ends in death.
There are 2 types of immunization:
People who are required to have immunization before exposure to the virus need 3 doses of the rabies vaccine (Human Diploid Cell Vaccine- HDVC). People who require immunization after contact need 5 doses. The vaccine protection starts 7- 10 days after injection and lasts for over a year.
The Rabies Immune globulin (RIG) contains antibodies that neutralize the virus, providing rapid protection; but, it only lasts a few weeks. Vaccine (HDVC) and immune globulin (RIG) should be used concurrently to help develop immune system.
Wild animals or unwanted animals that are suspected of having rabies are humanely killed. Their heads are submitted for laboratory examination.
Today, many states are vaccinating animals in the wildlife by putting oral vaccines in special bait to prevent the spread of rabies. The baits are dropped from planes or placed in wildlife areas where the animals will eat the vaccine in the food. This helps them from getting rabies if they are bitten by a rabid animal.
Interesting facts about rabies…
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Louis Pasteur and Emily roux developed the first rabies vaccination in 1855.
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There is only one known case (Jenna Giese) of survival in which the patient received no rabies specific treatment either before or after the illness.
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Infections of rabies through corneal treatment have been reported in
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From 1925 to 1035, 89 people and thousand s of livestock died from bat rabies in Trinidad in
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The first written record of rabies is in the Codex of Eshunna, which indicates if a person is bitten by a rabid dog and later dies, the owner is to be fined heavily.
By Roberta Loo Blk. D