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The information in blue
gives a quick overview, while the black text provides more detail.
WHY SHOULD I READ ALL OF THIS?
You don't have to read ALL of this. You SHOULD read at least the blue text in any answers. (The black text provides more detailed information for those wishing same.) WHY? Because when it comes to rabies, ignorance can kill. Not just you or your pets, but innocent and healthy wildlife. Raccoons are the number one wild animal killed for rabies testing. Dogs and cats top the list of domestic animals killed for rabies testing. In both these and other animals, the vast majority are found NOT to have rabies. They must pay with their lives because people have possibly been exposed to rabies by them. If these same people had taken precautions against possible exposure to rabies, these animals would still be alive. Don't be responsible for the death of an innocent animal. Learn about rabies and learn how to protect yourself, your family, your pets and our wildlife.
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WHAT IS RABIES?
Rabies is a virus germ with several kinds or strains that attacks the brain (and central nervous system) of warm-blooded animals (mammals). It uses foxes, skunks, bats and raccoons as carriers to spread the disease. It can spread to other wild or domestic animals, including cats and dogs, and to humans. The virus proves fatal to most infected animals and humans. It can kill a person who is not treated and has had contact with an animal that has rabies. The disease can cause confusion, breathing problems and fits (seizures). These signs may not show up for two to eight weeks or more. By then, there is no cure and the person will probably die. Rabies is described in medical writings dating from 300 BC, but how it was trasmitted was not known until 1804. In 1884 the French bacteriologist Louis Pasteur developed a vaccine to prevent rabies, and modifications of Pasteur's methods are still used today. In 1885, Pasteur created the first successful vaccine against rabies for a young boy who had been bitten 14 times by a rabid dog. Over a period of ten days, Pasteur injected stronger and stronger rabies virus into the boy, causing the boy to develop immunity in time to save his life.
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Rabies (Hydrophobia) is a serious zoonitic (can pass from animal to human) virus infection of the central nervous system and is found in the saliva and certain body materials (brain tissue or cerebral spinal fluid, for example) of rabid animals and humans. Animals that are commonly infected include dogs (especially wild dogs), bats, skunks, foxes, coyotes, and raccoons. Due to a lack of dog vaccination and control programs, dogs remain the major vector in Third World countries. Other common vectors are domestic cats, jackals, mongooses and, particularly in countries in western Asia, wolves. However, the range of infected animals in Third World countries is so wide (including livestock and rodents) that rabies should be suspect in any animal bite. Although some mammals are more susceptible to some strains of rabies, any animal can be infected by any strain of rabies. It is transmitted by the saliva of an infected animal that passes to humans (or other animals) through broken skin or a mucous membrane. The virus travels slowly from the bite area to the brain. Body parts involved include the central nervous system--including the brain, the coverings of the brain (meninges), and the spinal cord – and peripheral nerves as well as body parts bitten by the rabid animal.
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WHAT IS RACCOON RABIES?
Raccoon rabies is a strain of rabies carried mainly by raccoons. Raccoon rabies is rabies. It can be spread to farm animals, pets and people through the saliva of an infected animal in the same ways as other strains of rabies. Raccoon rabies kills raccoons, other animals and humans in the same way as other strains of rabies do. The only difference is that it is spread primarily by raccoons.
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Raccoon rabies was first noted in Florida in the 1940s. This strain of rabies virus in the raccoon population has slowly spread northward from the southern United States. Since 1977, rabies among raccoons has become an epizootic (a disease affecting many animals of one kind at the same time), spreading steadily northward from the Central Atlantic States. The epizootic finally reached the southern tier of New York State in 1990. In 1993, the first case of rabies in raccoons resulting from this epizootic was confirmed in New York State and in 1995 the state showed continued spread of raccoon rabies into previously unaffected areas and a second wave of rabid raccoons in areas first affected by the rabies epizootic. It is now well established in New York. This raccoon rabies, a strain not found in Ontario, is now at Ontario's southern border where it will not cross without a fight from a very prepared government. The raccoon rabies epizootic is also moving westward from Pennsylvania into Ohio. For more on raccoon rabies, see "What is being done to stop the spread of rabies?" near the bottom of this document.
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IS IT TRUE THAT NO HUMAN EVER CONTRACTED RACCOON RABIES?
Last month it was true that no human ever contracted raccoon rabies. Last week it was true also. But what about today? Tomorrow? Note too that most people seek recommended (and in some areas legally required) medical attention following possible exposure to raccoon rabies, thereby almost completely eliminating the risk of contracting the disease. The first human who contracts raccoon rabies will, in all probability, die. And although no human rabies cases have been associated with the raccoon rabies epizootic, the number of people receiving postexposure prophylaxis (average cost: $1,500 per patient) for potential exposures to rabid animals have increased dramatically in states affected with the raccoon rabies epizootic. Do not panic and think that every raccoon you see is rabid. Respect the fact that they, along with foxes, skunks, etc., are wild animals and that COULD carry rabies and avoid contact.
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HOW DO YOU GET RABIES? HOW IS RABIES TRANSMITTED?
Rabies is carried in an animal's saliva. You can get rabies if you are bitten or sometimes even scratched or licked by an animal that has rabies or if its saliva comes into contact with a cut or a scratch, or the moist tissues of your mouth, nose or eyes.
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Rabies is usually contracted from the bite of a rabid animal, but on rare occasions, contact of virus-laden saliva with broken skin or moist tissues of the mouth, nose or eyes may be sufficient to transmit infection. Bites to the face and hands carry especially high risk. Less common modes of transmission include scratches from animals with contaminated claws; contamination of mucous membranes or scraped skin with infected saliva (as a result of licks, for example) or with infected body material, unless the material is dry. The saliva of an infected animal can spread rabies even before there are any signs of the disease. In rare instances, airborne spread can also occur, as has been demonstrated in caves densely inhabited by infected bats. Skunks have been infected experimentally by being fed infected animals, hopefully for the purpose of trying to develop a lasting vaccine. In recent years, there have been four reported cases of human-to-human rabies transmission by corneal transplants.
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HOW CAN YOU TELL IF AN ANIMAL HAS RABIES?
Animals with rabies often change their behavior. Some animals may become depressed and lose their fear of humans, while others show extreme excitement and aggression. In early stages of the disease, the animal may show no signs at all. Pets may lose their appetites or become unusually aggressive, depressed or lethargic (sluggish). The animals' movements may seem awkward and stiff. Wild animals may seem friendly or become unusually aggressive. Night-roamers like raccoons and skunks may wander about in daylight. But remember some usually nocturnal animals, like raccoons, may be out in the daytime just looking for food – especially if it is a mother raccoon who has babies still in the den or a raccoon whose natural habitat has just been destroyed. If you think an animal has rabies stay away from it. If it is a family pet, isolate it. Do not get saliva from the animal on your skin. Immediately call your veterinarian, humane society or animal control agency. The rabies virus can be found in animal saliva days before any obvious symptoms develop. However, all animals that have the virus will develop symptoms and eventually die of the disease. Some symptoms of distemper may be mistaken for rabies. Canine distemper is also a viral disease, spread by direct or indirect contact. It kills more raccoons than any other disease. It has wiped out complete raccoon populations in some areas. It is the prime cause of death of young raccoons. Canine distemper cannot be transmitted to humans. All warm-blooded animals can transmit rabies, however.
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Rabies can manifest itself as "dumb" (paralytic) or "furious" (irritable) rabies.
In dumb rabies some animals may become depressed and retreat to isolated places; wild animals, especially skunks and raccoons, may lose their fear of humans; animals may show signs of paralysis such as abnormal facial expressions, drooping head, sagging jaw, or paralyzed hind limbs. The stages of furious rabies are similar to those through which an infected human passes. In furious rabies animals may show extreme excitement and aggression, gnaw and bite their own limbs, and attack stationary things or other animals. These bouts of furious rabies usually alternate with periods of depression.
Early signs of rabies in animals include altered disposition, fever, loss of appetite, and often, altered phonation, such as a change in tone of a dog's bark. These signs are often slight, however, and may escape notice. After a few days, marked restlessness and agitation may develop, along with trembling. An affected dog may growl and bark constantly and will viciously attack any moving object, person, or animal it encounters. If not restrained, it may leave home and travel great distances, inflicting much damage as it goes. This excited state usually lasts three to seven days and is followed by convulsions and paralysis. In some instances, signs of excitement and irritability are slight or absent, and paralysis develops within a few days of disease onset. In cases of this type, an early sign is often paralysis of the lower jaw, accompanied by increased salivation. This may cause the animal to appear to be choking on a foreign object, constituting a dangerous trap for humans, who, in attempting to be helpful, may unwittingly expose themselves to infection.
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WHAT SHOULD I DO IF I AM EXPOSED TO RABIES?
If you think you have made contact with a rabid animal immediately wash the affected skin area with soap and water. Call your doctor or clinic or go to the nearest hospital emergency department. If saliva from the animal is on your clothing, wash it immediately in hot, soapy water BUT DO NOT TOUCH THE SALIVA.
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After a person is bitten or otherwise exposed, a physician should be reached as soon as possible. One valuable preventive measure is to clean the wound immediately with soap and water or even water alone to remove saliva from the area. The wound may then be squeezed to promote bleeding, since this will also help to clean it. If the animal is killed do not dispose of it until you have advised the physician or health department and inquired as to preserving the head until it can be examined by pathologists. Don't panic. The incubation period allows time for diagnosis and treatment.
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WHAT SHOULD I DO IF I THINK MY PET HAS BEEN EXPOSED TO RABIES?
The aggressive behavior of some infected raccoons will sometimes prompt it to attack humans, but more often it will end up tangling with a pet, usually a dog or a cat. That is why it is critical for pets to receive the rabies vaccine. Make sure your dogs or cats have their rabies shots when they are supposed to – KEEP YOUR PETS’ RABIES SHOTS UP TO DATE!! Dogs and cats often get into fights with wild animals. If you witness a fight, or if your dog or cat comes home with injuries from a fight and you think your pet may have made contact with a rabid animal, don't handle your pet. There may be fresh saliva from the rabid animal on its coat. However, to reduce the risk of your pet's becoming infected, some sources recommend that the exposed areas, especially cuts and scratches, should be washed with soap and warm water as soon as possible. Elbow length rubber gloves should be worn while doing this. Isolate the pet at once. Contact your veterinarian, animal control agency, humane society branch. Your vet may require that the pet have a booster dose of the vaccine within five days of exposure. If your pet’s rabies vaccinations are not up to date, it may have to be quarantined (up to four months) until the incubation period has safely passed or, if the pet if infected, it dies or is destroyed. There is no treatment for animals infected with rabies - only death. So be smart, make sure your pets’ vaccinations are up to date now!
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WHAT SHOULD BE DONE WITH THE SUSPECTED RABID ANIMAL?
If at all possible, a dog or cat inflicting a bite should be captured alive and kept under surveillance. This may make it possible for the bitten individual to avoid undergoing rabies vaccination unnecessarily. While such postexposure prophylaxis is not painful as it was in the past (when a series of 23 needles was injected into the stomach wall), it is expensive, with the average cost in 1997 being $1,500 per patient. If the animal remains healthy under confinement and veterinary observation for the quarantine period (up to four months in an unvaccinated animal!), it is usually assumed to not be infected. If, however, the animal becomes ill or dies, the local health department should be notified immediately and steps taken to ascertain whether the illness is rabies.
When the dog or cat cannot be captured alive, but must be killed, damage to the brain should be avoided. The head will be sent to the diagnostic facility indicated by the local health department. Do not dispose of the animal until you have advised the physician or health department and inquired as to preserving the head until it can be examined by pathologists.
While new methods of diagnosis in living animals are under study, most authorities recommend or require that any wild animal that bites a person without provocation should be killed and the brain examined immediately for rabies. It is not known how long virus is present in the saliva of wild animals prior to their showing clinical signs of rabies.
If you try to touch a wild animal, it might bite you because it has rabies. It might bite you because it is scared. It might bite you because it is a mother with babies nearby. Because it bit you, the animal must be killed and tested for rabies. Protect yourself. Protect wildlife. Don’t touch!
The simple act of possibly having exposed yourself to rabies from a possibly infected animal such as a raccoon can result in a perfectly healthly animal being killed so that it’s head can be sent for testing! Save wildlife. See how to protect yourself and your pets from rabies!
If the biting animal escapes or is unknown, determination of the probable risk of rabies must be made by a local physician. The degree of risk is judged on the basis of such factors as the prevalence of rabies in the area, the species of the biting animal, the severity of the wound or wounds, and whether the attack was provoked or unprovoked. Only your doctor, clinic or hospital can make this judgment.
Excepting Third World countries, rodents, including squirrels, are rarely infected and unless a bite was entirely unprovoked, the possibility of rabies is usually dismissed. Check with your doctor. Bat bites, on the other hand, are small and may possibly go unnoticed, so postexposure treatment may be advised after physical contact with bats unless bite or mucous membrane exposure can be reliably ruled out. Contact a doctor whenever there is the possibility of exposure.
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HOW LONG DOES IT TAKE TO GET RABIES AFTER INFECTION (INCUBATION PERIOD)?
If the animal or person is infected, the time between exposure to the virus and the beginning of symptoms can range from about two weeks to many months. One to two months is about average but, in rarer cases, symptoms can develop in as little as five days to up to a year or more.
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The bite of a rabies-infected animal does not invariably cause disease, but when symptoms do appear it is usually 30 to 50 days following exposure. In dogs, this incubation period is shorter, generally 14 to 60 days. There is a direct relationship between the severity and location of the bite and the length of the incubation period. If the head of an animal or a person is severely bitten, symptoms may appear in as few as 14 days or less. Under rare circumstances illness may not develop for a year or more. A key factor in determining how quickly rabies will develop is how close the virus comes to nerve endings when the bite or other exposure occurs. The farther it is from nerve endings, the longer it takes to reach the nervous system and develop an infection; therefore, postexposure treatment with vaccines can still be effective in preventing rabies even if you were not able to get treatment immediately. So always seek treatment; don't think you've missed your chance. Once symptoms begin, survival is unlikely. The mortality rate is 80%. [top]
WHAT ARE THE SYMPTOMS OF RABIES IN HUMANS?
Rabies in a human is suspected if, weeks or months after exposure to the disease, an individual experiences symptoms such as: a short period of mental depression, restlessness and irritability, abnormal sensations around the site of exposure, headache, slight fever, malaise, fatigue, nausea, cough, sore throat, or loss of appetite. Other early symptoms include unusual sensitivity to sound, light and changes of temperature, muscle stiffness, dilation of pupils and increased salivation. As the disease progresses, the patient usually experiences episodes of irrational excitement or dementia, confusion, hyperactivity and violent behavior alternating with periods of alert calm; high fever, irregular heartbeat, irregular breathing. Convulsions are common. Most dramatic of all are the severe and extremely painful violent throat spasms suffered by the victim on attempting drinking, which usually results in terror at the mere sight of water and gives the disease its common name, hydrophobia.
Death from cardiac or respiratory failure usually occurs within a week after appearance of rabies symptoms, while the excited state is still predominant. If the patient survives this stage, muscle spasms and agitation cease, only to be replaced by fatal progressive paralysis, coma, and almost always death. In human rabies resulting from the bite of a rabid vampire bat, excitement and hydrophobia are typically absent, and the disease is characterized by paralysis progressing from the legs upward.
Once symptoms appear, the only treatment is vigorous supportive measures to control the respiratory, circulatory, and central nervous system symptoms. Recovery has occurred in a few cases despite the general opinion that rabies in humans is invariably fatal.
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HOW IS RABIES CONFIRMED (DIAGNOSED)?
Clinical diagnosis of rabies in humans is based on the patient's history of exposure and development of characteristic symptoms. To confirm the diagnosis (usually not possible until late in the disease), rabies virus must be demonstrated in saliva or brain tissue. The virus may be identified on the basis of animal inoculation tests or specific staining with fluorescent antibodies. Other useful diagnostic procedures include identification of rabies antibodies in the patient's blood or cerebrospinal fluid and demonstration of characteristic Negri bodies in samples of brain tissue.
Diagnosis of rabies in animals is similar, in most respects, to the procedure in humans, but the disease is easier to confirm at an early stage, since the animal can be killed for detailed brain studies. While new methods of diagnosis in living animals are under study, wild animals are almost exclusively killed for testing. So avoid any possible exposure and help to save wildlife. Animals that die after long periods of illness may not have infectious virus in the brain due to the so-called "auto-sterilization" phenomenon. In that event, the tissue or spinal fluid may be tested for antibodies.
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IS RABIES TREATABLE?
Anyone possibly exposed to rabies should seek medical attention immediately. Anyone who is exposed to rabies should be treated immediately. Currently, there is no regular treatment for animals which were not previously vaccinated against rabies.
Rabies is fatal if untreated. The treatment which is safe and effective is usually a series of five shots in the arm given over a one-month period. If a physician determines that an individual probably has been exposed to rabies postexposure treatment may begin at once. Treatment includes both passive and active immunization and is effective when appropriately used. Passive immunization provides immediate but transitory protection by the injection of antibody from an outside source. Active immunization stimulates production of one's own antibodies, which requires a period of time, but provides longer lasting protection.
The current recommended antirabies immunization treatment is passive immunization with one dose of human rabies immune globulin (RIG) and active immunization with killed rabies virus vaccine. Generally, vaccines made with killed viruses can only prevent disease when they are used before exposure. However, rabies has an unusually long incubation period, and there is time for the body to respond to the vaccine and produce protective antibodies. The newer rabies vaccine, human diploid cell vaccine (HDCV), is produced from viruses grown in cultures of human cells. This vaccine is safer and more effective than the previously used duck embryo vaccine (DEV) which, until early in the 1980’s, was the only vaccine used in the United States. It was less efficient in producing immunity and required 23 injections into the stomach wall. Ouch!
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Post-exposure immunization with HDCV requires only five intramuscular injections (into the muscle) of the upper arm over a four-week period. The vaccine schedule calls for five 1-milliliter (ml.) doses on days 0, 3, 7, 14, and 28 after exposure. The incidence of mild systemic reactions, e.g., headache, fever, nausea, muscle aches, and dizziness, is lower with HDCV than with DEV. Although HDCV is a great improvement over previous vaccines, it is relatively expensive to produce because it propagates poorly in cell cultures, and needs to be highly concentrated and purified. Cost of treatment can exceed $1,500.00.
For this reason, investigators are still seeking improved vaccines and other means of rabies control. The human diploid cell antirabies vaccine (HDCV) has been produced by Pasteur Merieux Connaught (PMC), Lyons, France, since the 1970s. In 1988, PMC put another cell-culture vaccine, PVRV (Purified Vero cell Rabies Vaccine), on the market. According to Henri Debois, Product Safety Officer of PMC, "PVRV can be readily produced on a large scale and exhibits, as compared to HDCV, similar immunogenicity and an improved safety profile after booster vaccination." Raul Melendez, Head of Clinical Research, Hoechst Marion Roussel, Mexico, in a paper entitled 'The Immunogenicity of PCEC Vaccine - A Review' states that "the PCEC (purified chick embryo cell) vaccine has proven efficacy and safety, similar to HDC (human diploid cell) vaccine,...with the advantage of being less expensive and more accessible in countries with endemic rabies." In a clinical study entitled 'Antibody Response And Safety Of Rabies PCEC Vaccine And HDC Vaccine Administered As A Primary Rabies Pre-Exposure Series In 165 Health Volunteers', Dr. David W. Dreesen, Professor, Department of Medical Microbiology & Parasitology, College of Veterinary Medicine, The University of Georgia, concluded that both vaccines "were equivalent in RNA at day 49 and for safety". The PCECV vaccine (RabAvert) is now licensed in the U.S.
Pre-exposure immunization with HDCV is recommended for persons with special risks of exposure to rabies, such as veterinarians, animal caretakers, laboratory workers, and yours truly and is usually given in three intradermal (within the skin) injections of the upper arm. If you are traveling to a Third World County, it may also be recommended. Check first. Studies are being conducted to help determine if currently accepted rabies vaccination regimens provide an adequate serological response in HIV/AIDS patients. The schedule for the vaccine is three 0.01-ml. doses on days 0, 7, and 21 or 28. People with continuing risk of exposure should receive a booster at least every two years. (My family and I just received our boosters on January 14, 1998. The intradermal injections, needles inserted just under the skin in the arm, are not painful and we have never had any reactions to the vaccine.)
Because it uses less vaccine, the is far less expensive than the intramuscular using larger doses with the same schedule. Both have been approved as effective for pre-exposure immunization but the vaccine by intradermal method does not take full effect until 30 days after the third dose. If you will be at risk sooner than 30 days after the third dose, you should get the vaccine by the intramuscular route, which takes effect much more quickly. Preexposure vaccination does not eliminate the need for postexposure vaccination - it just means that fewer postexposure shots are needed. (Exposed persons who were not previously vaccinated require more vaccine doses, plus injections of rabies immune globulin.) The people with special risks can sometimes be exposed to rabies without realizing it. If, however, you are aware of the possible exposure, then, even though you have had pre-exposure immunization, you should report the incident immediately and ascertain what post-exposure immunization or booster is required.
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IS THE RABIES VACCINE SAFE?
It is considered safe for everyone, even infants and during pregnancy, but as always, check with your doctor. Some people have mild pain, swelling, redness or itching for a few days where the needle was given. A few people may have headaches, loss of appetite, stomach pain, muscle aches or dizziness. Serious side effects are rare. Call your doctor if you have any questions or if any of these symptoms happen within three weeks after being vaccinated: hives, vomiting high fever, convulsions or seizures, any other serious health problems.
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HOW CAN I PROTECT MYSELF AND MY PETS AGAINST RABIES?
Because there is no cure for rabies, prevention and protection is vital!
April 9, 2000 Update |