rabies

(rā`bēz, ră`–) or

hydrophobia

(hī'drəfō`bēə), acute viral infection of the central nervous system in dogs, foxes, raccoons, skunks, bats, and other animals, and in humans. The virus is transmitted from an animal to a person, or from one animal to another, via infected saliva, most often by biting but also by the contact of torn skin with infected saliva. The virus travels from the bite or contact location to the spinal cord and brain. In humans the incubation period ranges from 10 days to a year or more. Symptoms are fever, uncontrollable excitement, and pronounced spasms of the throat muscles. Salivation is extreme, and despite great thirst the victim cannot swallow water; hence the misnomer hydrophobia (fear of water). Once symptoms develop, death (caused by convulsions, exhaustion, or paralysis) is usually inevitable.

Following a bite from a rabid or possibly rabid animal, preventive treatment involves administration of immune globulin for passive immunization followed by vaccinations over several weeks for active immunization. The only treatment after symptoms appear is rest and sedation. Dogs have been immunized from the time Louis PasteurPasteur, Louis
, 1822–95, French chemist. He taught at Dijon, Strasbourg, and Lille, and in Paris at the École normale supérieure and the Sorbonne (1867–89).
..... Click the link for more information. demonstrated a successful vaccine in 1885. Since then, human rabies has become rare in the United States and other industrialized countries due to comprehensive vaccination programs for domestic animals. Mass vaccination of susceptible animals in the wild with vaccine-laced bait has been used in an effort to stem an increase of rabies cases in the United States and Canada that began in the late 1980s. A similar wild animal vaccination program has been used with some success in parts of Europe.

Rabies

An acute, encephalitic viral infection. Human beings are infected from the bite of a rabid animal, usually a dog. Canine rabies can infect all warm-blooded animals, and death usually results. See Animal virus

The virus is believed to move from the saliva-infected wound through sensory nerves to the central nervous system, multiply there with destruction of brain cells, and thus produce encephalitis, with severe excitement, throat spasm upon swallowing (hence hydrophobia, or fear of water), convulsions, and death—with paralysis sometimes intervening before death.

All bites should immediately be cleaned thoroughly with soap and water, and a tetanus shot should be considered. The decision to administer rabies antibody, rabies vaccine, or both depends on four factors: the nature of the biting animal; the existence of rabies in the area; the manner of attack (provoked or unprovoked) and the severity of the bite and contamination by saliva of the animal; and recommendations by local public health officials.

Diagnosis in the human is made by observation of Negri bodies (cytoplasmic inclusion bodies) in brains of animals inoculated with the person's saliva, or in the person's brain after death. A dog which has bitten a person is isolated and watched for 10 days for signs of rabies; if none occur, rabies was absent. If signs do appear, the animal is killed and the brain examined for Negri bodies, or for rabies antigen by testing with fluorescent antibodies. See Viral inclusion bodies

Individuals at high risk, such as veterinarians, must receive preventive immunization. If exposure is believed to have been dangerous, postexposure prophylaxis should be undertaken. If antibody or immunogenic vaccine is administered promptly, the virus can be prevented from invading the central nervous system. An inactivated rabies virus vaccine is available in the United States. It is made from virus grown in human or monkey cell cultures and is free from brain proteins that were present in earlier Pasteur-type vaccines. This material is sufficiently antigenic that only four to six doses of virus need be given to obtain a substantial antibody response. See Vaccination

Rabies

hydrophobia, an acute infectious disease that is caused by a neurotropic virus and that affects the central nervous system. Animal rabies has been known since ancient times; it is mentioned by Democritus, Aristotle, and others. Louis Pasteur showed through his investigations that the causative agent of rabies is concentrated in the central nervous system. In 1887 the Rumanian scientist V. Babes, and in 1903 the Italian physician A. Negri discovered in the brains of dead victims of rabies special inclusion bodies measuring 1–27 microns. The nature of these inclusions—Babeş-Negri bodies—has not been fully clarified, but their detection has absolute diagnostic significance. When a person is bitten by a dog or other animal suspected of carrying rabies, the animal must be isolated for further observation. If the animal does not die within ten days, rabies is usually precluded. If it does die within this period, discovery of Babeş-Negri bodies in its brain confirms a diagnosis of rabies.

Although the proportion of rabies among other infectious diseases of animals is not great, rabies infections are found all over the world. Mammals, mainly members of the canine family, are affected by rabies under natural conditions. Among domestic animals, the most numerous of those infected are cattle (up to 55 percent), dogs (27 percent), sheep and goats (11 percent), pigs (5 percent), and horses (2 percent). In the USSR the majority of cases occur in the early months of the year (January to May). Wild carnivores play the most important role in spreading rabies among agricultural animals. Infection of animals with rabies occurs only as a result of the entry of the saliva of the infected animal through breaks in the skin or mucous membrane, usually by a bite. The latent period of rabies in animals lasts one to two months (in up to 90 percent of cases), more rarely up to six months. Its duration depends mainly on age (the younger the animal, the shorter the latent period) and the site, size, and depth of the bite (with deep, numerous, extensive wounds and bites in the head area the incubation period is shortened).

The five clinical forms of rabies that are commonly distinguished in animals are (1) abortive, in which recovery occurs after initial typical symptoms; (2) relapsing, in which the animal dies after temporary improvement; (3) atypical, which is chronic and accompanied by emaciation; (4) furious (most typical), in which aggressiveness is manifested by the animal and there is perversion of the appetite (ingestion of inedible objects) and paralysis of the pharynx; and (5) quiet, which is characterized by a less expressive period of excitement. Rabies proceeds most typically in dogs. In cats the illness usually proceeds in its furious form; in cattle, sheep, and goats, in its furious and quiet forms; in pigs, in sharply expressed violent form.

Treatment of animals infected with rabies is prohibited; they are to be immediately destroyed. Prophylaxis is directed toward immunizing animals, destroying stray dogs and cats, and shooting and trapping animals that make up reservoirs of rabies.

Infection of man with rabies occurs by a bite or lick on the skin or mucous membranes by a rabid animal whose saliva contains the causative agent of rabies. Especially dangerous for man are bites of a rabid animal on the head, face, or neck; in such cases the incubation period of the disease is shortened and the illness proceeds with special virulence. Having penetrated the human body through a wound inflicted by the bite of a rabid animal (or a licked scratch), the virus spreads along nerve trunks toward the central nervous system, affecting the nerve centers and the cerebral cortex.

The following are distinguished in the clinical history in man: (1) the stage of depression of the central nervous system, lasting from several hours to 48 hours; (2) the stage of excitement, hallucinations, and motor agitation (from four to seven days); (3) the stage of paralysis (from several hours up to two to three days), ending in the death of the patient. The latent (incubation) period calculated from the moment of the bite or lick by a rabid animal to the first manifestations of the disease lasts from 15 to 55 days. At first a dull aching pain begins at the site of the bite, continuing even when the wound is closed. The patient’s mood is depressed, his sleep is restless. Various hallucinations appear—visual, auditory, and olfactory—usually menacing in character. After a comparatively short period of depression, motor excitement and noisy breathing develop, and the patient is excited and alarmed and complains of lack of air. Then muscular convulsions develop, mostly of the musculature of the pharynx; at the mere sight of a glass of water or at the sound of running water the patient develops reflex spasms of the pharyngeal musculature, making ingestion of food and drink impossible. All the senses, including vision and hearing, are significantly sharpened; any stimuli (a light breeze blowing, the touching of the patient’s body’, the effects of bright light or loud sounds) lead to the development of muscle convulsions and spasms of the pharyngeal musculature. Beginning with the second or third day of the illness, speech becomes incoherent, hallucinations are intensified, the patient thrashes around in bed, tries to run away, and so on. Convulsive attacks become more frequent as the disease progresses. Abundant salivation is noted. Soon paralysis of the upper and lower extremities occurs; the patient dies of paralysis of the heart. The temperature remains normal or is slightly elevated (37.3°–37.4° C) for the duration of the disease.

Treatment consists of symptomatic measures that prevent convulsions and act as analgesics and somnifacients. Feeding is done artificially. Prophylaxis consists of injection of a person who has been bitten by a rabid animal with antirabies vaccine; vaccination must be started as early as possible and without fail before the 14th day from the moment of infection, since it produces nonsusceptibility to rabies in the patient no earlier than two to three weeks from the beginning of its injection. Given in good time, the injections are a reliable means of preventing the development of rabies.

REFERENCES

Rudnev, G. P. Zoonozy, 2nd ed. Moscow, 1959.
Bunin, K. V. Diagnostika infektsionnykh boleznei. Moscow, 1965.
Nazarov, V. P. Beshenstvo zhivotnykh. Moscow, 1961.

K. V. BUNIN

rabies

[′rā·bēz] (veterinary medicine) An acute, encephalitic viral infection transmitted to humans by the bite of a rabid animal. Also known as hydrophobia.

rabies

Pathol an acute infectious viral disease of the nervous system transmitted by the saliva of infected animals, esp dogs. It is characterized by excessive salivation, aversion to water, convulsions, and paralysis

rabies

Rabies

Definition

Rabies is an acute viral disease of the central nervous system that affects humans and other mammals but is most common in carnivores (flesh-eaters). It is sometimes referred to as a zoonosis, or disease of animals that can be communicated to humans. Rabies is almost exclusively transmitted through saliva from the bite of an infected animal. Another name for the disease is hydrophobia, which literally means "fear of water," a symptom shared by half of all people infected with rabies. Other symptoms include fever, depression, confusion, painful muscle spasms, sensitivity to touch, loud noise, and light, extreme thirst, painful swallowing, excessive salivation, and loss of muscle tone. If rabies is not prevented by immunization, it is almost always fatal.

Description

Cases of rabies in humans are very infrequent in the United States and Canada, averaging one or two a year (down from over 100 cases annually in 1900), but the worldwide incidence is estimated to be between 30,000 and 50,000 cases each year. These figures are based on data collected by the World Health Organization (WHO) in 1997 and updated in 2002. Rabies is most common in developing countries in Africa, Latin America, and Asia, particularly India. Dog bites are the major origin of infection for humans in developing countries, but other important host animals may include the wolf, mongoose, raccoon, jackal, and bat. A group of researchers in India found that monkeys as well as dogs were frequent vectors of rabies. The team also reported that the male:female ratio of rabies patients in India is 4:1.Most deaths from rabies in the United States and Canada result from bat bites; the most recent fatality was a 66-year-old man in California who died in September 2003. The death of a nine-year-old girl in Quebec in the fall of 2000 was the first case of human rabies in Canada since 1985. Public health officials eventually determined that the girl had been bitten while she was sleeping by a silver-haired bat that had gotten into the family's home.On October 18, 2004, a Wisconsin teenager was diagnosed with full-blown rabies after suffering from a minor bat bite on September 12, 2004. Miraculously, she was cured of rabies after doctors induced coma and administered four antiviral drugs to her. Since the therapy was only given and successful for one case, its curative properties needs to be corroborated by other cases before it will be considered a viable treatment option. The case and the physicians' findings will be published in a medical journal.People whose work frequently brings them in contact with animals are considered to be at higher risk than the general population. This would include those in the fields of veterinary medicine, animal control, wildlife work, and laboratory work involving live rabies virus. People in these occupations and residents of or travelers to areas where rabies is a widespread problem should consider being immunized.In late 2002, rabies re-emerged as an important public health issue. Dr. Charles E. Rupprecht, director of the World Health Organization (WHO) Collaborating Center for Rabies Reference and Research, has listed several factors responsible for the increase in the number of rabies cases worldwide:

Rapid evolution of the rabies virus. Bats in the United States have developed a particularly infectious form of the virus.
Increased diversity of animal hosts for the disease.

Changes in the environment that are bringing people and domestic pets into closer contact with infected wildlife.
Increased movement of people and animals across international borders. In one recent case, a man who had contracted rabies in the Philippines was not diagnosed until he began to feel ill in the United Kingdom.
Lack of advocacy about rabies.

Causes and symptoms

Rabies is caused by a rod- or bullet-shaped virus that belongs to the family Rhabdoviridae. The rabies virus is a member of a genus of viruses called lyssaviruses, which include several related viruses that infect insects as well as mammals. The rabies virus is usually transmitted via an animal bite, however, cases have also been reported in which the virus penetrated the body through infected saliva, moist tissues such as the eyes or lips, a scratch on the skin, or the transplantation of infected tissues. Inhalation of the virus in the air, as might occur in a highly populated bat cave, is also thought to occur.From the bite or other area of penetration, the virus multiplies as it spreads along nerves that travel away from the spinal cord and brain (efferent nerves) and into the salivary glands. The rabies virus may lie dormant in the body for several weeks or months, but rarely much longer, before symptoms appear. Initially, the area around the bite may burn and be painful. Early symptoms may also include a sore throat, low-grade fever, headache, loss of appetite, nausea and vomiting, and diarrhea. Painful spasms develop in the muscles that control breathing and swallowing. The individual may begin to drool thick saliva and may have dilated or irregular pupils, increased tears and perspiration, and low blood pressure.Later, as the disease progresses, the patient becomes agitated and combative and may exhibit increased mental confusion. The affected person usually becomes sensitive to touch, loud noises, and bright lights. The victim also becomes extremely thirsty, but is unable to drink because swallowing is painful. Some patients begin to dread water because of the painful spasms that occur. Other severe symptoms during the later stage of the disease include excessive salivation, dehydration, and loss of muscle tone. Death usually occurs three to 20 days after symptoms have developed. Unfortunately, recovery is very rare.

Diagnosis

After the onset of symptoms, blood tests and cerebrospinal fluid (CSF) analysis tests will be conducted. CSF will be collected during a procedure called a lumbar puncture in which a needle is used to withdraw a sample of CSF from the area around the spinal cord. The CSF tests do not confirm diagnosis but are useful in ruling out other potential causes for the patient's altered mental state.The two most common diagnostic tests are the fluorescent antibody test and isolation of the rabies virus from an individual's saliva or throat culture. The fluorescent antibody test involves taking a small sample of skin (biopsy) from the back of the neck of the patient. If specific proteins, called antibodies, that are produced only in response to the rabies virus are present, they will bind with the fluorescent dye and become visible. Another diagnostic procedure involves taking a corneal impression in which a swab or slide is pressed lightly against the cornea of the eye to determine whether viral material is present.

Treatment

Until the most recent successful cure of a late-term rabies case can be validated with further success and validation from the medical community, the historic treatment options for rabies prevention immediately following a bite remains the most viable treatment. Because of the extremely serious nature of a rabies infection, the need for rabies immunizations will be carefully considered for anyone who has been bitten by an animal, based on a personal history and results of diagnostic tests.If necessary, treatment includes the following:

The wound is washed thoroughly with medicinal soap and water. Deep puncture wounds should be flushed with a catheter and soapy water. Unless absolutely necessary, a wound should not be sutured.
Tetanus toxoid and antibiotics will usually be administered.
Rabies vaccination may or not be given, based on the available information. If the individual was bitten by a domestic animal and the animal was captured, the animal will be placed under observation in quarantine for ten days. If the animal does not develop rabies within four to seven days, then no immunizations are required. If the animal is suspected of being rabid, it is killed, and the brain is examined for evidence of rabies infection. In cases involving bites from domestic animals where the animal is not available for examination, the decision for vaccination is made based on the prevalence of rabies within the region where the bite occurred. If the bite was from a wild animal and the animal was captured, it is generally killed because the incubation period of rabies is unknown in most wild animals.
If necessary, the patient is vaccinated immediately, generally through the administration of human rabies immune globulin (HRIG) for passive immunization, followed by human diploid cell vaccine (HDCV) or rabies vaccine adsorbed (RVA) for active immunization. Passive immunization is designed to provide the individual with antibodies from an already immunized individual, while active immunization involves stimulating the individual's own immune system to produce antibodies against the rabies virus. Both rabies vaccines are equally effective and carry a lower risk of side effects than some earlier treatments. Unfortunately, however, in underdeveloped countries, these newer vaccines are usually not available. Antibodies are administered to the patient in a process called passive immunization. To do this, the HRIG vaccine is administered once, at the beginning of treatment. Half of the dose is given around the bite area, and the rest is given in the muscle. Inactivated viral material (antigenic) is then given to stimulate the patient's own immune system to produce antibodies against rabies. For active immunization, either the HDCV or RVA vaccine is given in a series of five injections. Immunizations are typically given on days one, three, seven, 14, and 28.

In those rare instances in which rabies has progressed beyond the point where immunization would be effective, the groundbreaking treatment involving a drug-induced coma and the administration of four different antiviral drugs will most likely be a radical treatment option. The traditional approach prior to October 2004 was to provide as much relief from pain and suffering as possible through medical intervention while waiting to see if survival was possible. The patient would be given medication to prevent seizures, relieve some of the anxiety, and relieve painful muscle spasms. Pain relievers would also be given. In the later stages, aggressive supportive care would be provided to maintain breathing and heart function. Survival via the traditional treatment is rare but can occur.

Prognosis

If preventative treatment is sought promptly, rabies need not be fatal. Immunization is almost always effective if started within two days of the bite. Chance of effectiveness declines, however, the longer vaccination is put off. It is, however, important to start immunizations, even if it has been weeks or months following a suspected rabid animal bite, because the vaccine can be effective even in these cases. If immunizations do not prove effective or are not received, rabies is nearly always fatal with a few days of the onset of symptoms.

Key terms

Active immunization — Treatment that provides immunity by challenging an individual's own immune system to produce antibody against a particular organism, in this case the rabies virus.Antibody — A specific protein produced by the immune system in response to a specific foreign protein or particle called an antigen.Biopsy — The removal of a small sample of tissue for diagnostic purposes.Efferent nerves — Nerves that convey impulses away from the central nervous system to the periphery.Fluorescent antibody test (FA test) — A test in which a fluorescent dye is linked to an antibody for diagnostic purposes.Lumbar puncture — A procedure that involves withdrawing a small sample of cerebrospinal fluid from the back around the spinal cord.Lyssavirus — A genus of viruses that includes the rabies virus and related viruses that infect insects as well as mammals.Passive immunization — Treatment that provides immunity through the transfer of antibodies obtained from an immune individual.Rhabdovirus — A type of virus named for its rod- or bullet-like shape. The rabies virus belongs to a family of viruses called Rhabdoviridae.Vector — An animal or insect that carries a disease-producing organism.Zoonosis — Any disease of animals that can be transmitted to humans. Rabies is an example of a zoonosis.As of October 2004, the medical community awaits the publication of findings by the doctors that administered a life-saving treatment that cured a Wisconsin teenager of full-blown rabies. Further test cases will prove whether or not this treatment option will be a historic development in the search for a cure for rabies.

Prevention

One promising preventive strategy that has been used since the early 2000s is the distribution of wildlife baits containing an oral vaccine against rabies. This strategy has been used in Germany to vaccinate wild foxes, which are frequent carriers of the disease in Europe. In the United States, veterinary researchers at Kansas State University have developed an oral vaccine for fruit bats; early trials of the vaccine have given promising results.The following precautions should be observed in environments where humans and animals may likely come into contact.

Domesticated animals, including household pets, should be vaccinated against rabies. If a pet is bitten by an animal suspected to have rabies, its owner should contact a veterinarian immediately and notify the local animal control authorities. Domestic pets with current vaccinations should be revaccinated immediately; unvaccinated dogs, cats, or ferrets are usually euthanized (put to sleep). Further information about domestic pets and rabies is available on the American Veterinary Medical Association (AVMA) web site.
Wild animals should not be touched or petted, no matter how friendly they may appear. It is also important not to touch an animal that appears ill or passive, or whose behavior seems odd, such as failing to show the normal fear of humans. These are all possible signs of rabies. Many animals, such as raccoons and skunks, are nocturnal and their activity during the day should be regarded as suspicious.
People should not interfere in fights between animals.
Because rabies is transmitted through saliva, a person should wear rubber gloves when handling a pet that has had an encounter with a wild animal.
Garbage or pet food should not be left outside the house or camp site because it may attract wild or stray animals.
Windows and doors should be screened. Some victims of rabies have been attacked by infected animals, particularly bats, that entered through unprotected openings.
State or county health departments should be consulted for information about the prevalence of rabies in an area. Some areas, such as New York City, have been rabies-free, only to have the disease reintroduced at a later time.
Preventative vaccination against rabies should be considered if one's occupation involves frequent contact with wild animals or non-immunized domestic animals.
Bites from mice, rats, or squirrels rarely require rabies prevention because these rodents are typically killed by any encounter with a larger, rabid animal, and would, therefore, not be carriers.
Travelers should ask about the prevalence of the disease in countries they plan to visit.

Resources

Books

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Central Nervous System Viral Diseases: Rabies (Hydrophobia)." Section 13, Chapter 162 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

Periodicals

Chhabra, M., R. L. Ichhpujani, K. N. Tewari, and S. Lal. "Human Rabies in Delhi." Indian Journal of Pediatrics 71 (March 2004): 217-220.Deshaies, D., P. A. Pilon, L. Valiquette, and J. Carsley. "A Public Health Intervention at the Time of a Case of Rabies in Quebec." [in French] Canadian Journal of Public Health 95 (March-April 2004): 138-141.Fooks, A. R., N. Johnson, S. M. Brookes, et al. "Risk Factors Associated with Travel to Rabies Endemic Countries." Journal of Applied Microbiology 94, Supplement (2003): 31S-36S."Human Death Associated with Bat Rabies—California, 2003." Morbidity and Mortality Weekly Report 53 (January 23, 2004): 33-35.Messenger, S. L., J. S. Smith, L. A. Orciari, et al. "Emerging Pattern of Rabies Deaths and Increased Viral Infectivity." Emerging Infectious Diseases 9 (February 2003): 151-154.Peters, C., R. Isaza, D. J. Heard, et al. "Vaccination of Egyptian Fruit Bats (Rousettus aegyptiacus) with Monovalent Inactivated Rabies Vaccine." Journal of Zoo and Wildlife Medicine 35 (March 2004): 55-59.Rosenthal, Elisabeth. "Girl is first to survive rabies without a shot." The New York Times November 25, 2004: A28.Smith, J., L. McElhinney, G. Parsons, et al. "Case Report: Rapid Ante-Mortem Diagnosis of a Human Case of Rabies Imported Into the UK from the Philippines." Journal of Medical Virology 69 (January 2003): 150-155.Stringer, C. "Post-Exposure Rabies Vaccination." Nursing Standard 17 (February 5-11, 2003): 41-42.Thulke, H. H., T. Selhorst, T. Muller, et al. "Assessing Anti-Rabies Baiting—What Happens on the Ground?" BMC Infectious Diseases 4 (March 9, 2004): 9.Weiss, R. A. "Cross-Species Infections." Current Topics in Microbiology and Immunology 278 (2003): 47-71.

Organizations

American Veterinary Medical Association (AVMA). 1931 North Meacham Road, Suite 100, Schaumburg, IL 60173-4360. http://www.avma.org.Centers for Disease Control and Prevention. 1600 Clifton Rd., NE, Atlanta, GA 30333. (800) 311-3435, (404) 639-3311. http://www.cdc.gov.Institut Pasteur. 25-28, rue du Dr. Roux, 75015 Paris, France. +33 (0) 1 45 68 80 00. http://www.pasteur.fr/haut_ext.html.

Other

CDC. "Epidemiology of Rabies." http://www.cdc.gov/ncidod/dvrd/rabies/Epidemiology/Epidemiology.htm.National Association of State Public Health Veterinarians, Inc. "Compendium of Animal Rabies Prevention and Control, 2003." Morbidity and Mortality Weekly Report Recommendations and Reports 52 (March 21, 2003) (RR-5): 1-6.

rabies

[ra´bēz, ra´be-ēz] an acute infectious disease of the central nervous system, which affects all warm-blooded animals, including humans. It is caused by an RNA virus of the genus Lyssavirus. The virus is often present in the host's saliva, and human infection is usually transmitted by the bite or lick of a rabid animal, such as a bat, wolf, dog, cat, or other mammal; it is sometimes transmitted by the respiratory route. The incubation period in humans is from one to three months, being shorter following bites near the brain.
The earliest symptoms are intermittent pain, numbness, tingling, or burning around the site of infection; soon afterward, generalized hyperexcitability occurs, followed by fever, paralysis of the muscles of swallowing, and glottal spasm brought on by the sight of fluids or the drinking of fluids, and by maniacal behavior. Convulsions, tetany, and respiratory paralysis are the inevitable terminal events in untreated cases. The diagnosis can be determined by viral isolation (from saliva, cerebrospinal fluid, urine) or by demonstration of neutralizing antibody, and after death by the appearance of cytoplasmic inclusion bodies (Negri bodies) in degenerated neurons.
Without adequate immunization and treatment a person who has been infected with rabies is not likely to survive.Prevention. All warm-blooded family pets (such as dogs, cats, and monkeys) should be vaccinated against rabies periodically.
It is also essential to learn to recognize a rabid animal. In the early “anxiety” stages, a rabid animal may have a change of temperament. Many, including wild animals, may become unusually friendly. The rabid animal may next enter a “furious” stage, in which it wanders about biting everything that moves, and even some things that do not move, such as sticks and stones. It then develops paralysis of the throat, which makes swallowing difficult. The name hydrophobia, “fear of water,” was given to the disease because it was observed that stricken animals avoided water. Actually, this is not because of fear of water, but because they cannot swallow. Saliva often drips from the animal's mouth and may be whipped into a foam.
Some animals pass directly from the anxiety stage to paralysis without becoming violent. This is called the “dumb” form of rabies. The animal may appear to have something caught in its throat. A dog with something in its throat usually tries to remove it, but a rabid dog will not do this. Eventually all of the rabid animal's muscles become paralyzed and it dies.Treatment. When a person is bitten by an animal, the wound should be washed thoroughly with soap and water, and then treated like any other wound. It is extremely important to seek emergency health care immediately. If possible, steps should be taken to find out if the biting animal has rabies, preferably by finding the animal and confining it for observation. When the biting animal must be killed in order to capture it, care must be taken to see that the head is not damaged, so that the brain can be examined to establish a diagnosis. If the biting animal cannot be caught for observation, the bitten person must be given antirabies treatment immediately.
Preventive treatment of suspected rabies is based on immunization by a series of vaccine and immune serum injections. When bites are in areas close to the head or in areas with many nerve endings, such as the hands, the virus may reach the brain quickly. In such cases treatment should start immediately, even though the suspected animal is still being observed.
Agents used to confer passive immunity are human globulin" >rabies immune globulin and serum" >anitrabies serum. Allergic reactions to the immune globulin are rare, making it the preferred agent. In response to administration of antirabies serum, an occasional patient may experience severe anaphylaxis, while others develop serum sickness; hence, this agent is given only when human rabies immune globulin is not available. In many patients, the serum antibodies produce permanent immunity only after the last booster. If active immunity has been established, however, it lasts a lifetime. If a patient does not have permanent immunity established by the vaccine, the Centers for Disease Control and Prevention should be contacted.
A more effective and less troublesome immunizing agent is the newer vaccine" >human diploid cell vaccine. It requires only five injections over 28 days.
There is no cure for rabies and once symptoms appear treatment can only be palliative. This includes sedation of the patient and provision of a quiet environment to reduce anxiety and relieve pain, administration of a powerful muscle relaxant (curare-like drugs) to reduce muscular contractions, and supportive measures to maintain urinary and respiratory function. Death occurs in 2 to 5 days.

ra·bies

(rā'bēz), Although the Latin word is correctly pronounced in three syllables, speakers of English virtually always reduce these to two.Highly fatal infectious disease that may affect all species of warm-blooded animals, including humans; transmitted by the bite of infected animals including dogs, cats, skunks, wolves, foxes, raccoons, and bats, and caused by a neurotropic species of Lyssavirus, a member of the family Rhabdoviridae, that has tropism for the central nervous system and the salivary glands; inhalation infection possbile (aerosolized virus in bat caves, attics). The symptoms are characteristic of a profound disturbance of the nervous system, for example, excitement, aggressiveness, and madness, followed by paralysis and death. In animals, clinical signs are variable, and sometimes drooling and tongue paralysis are the only signs. Transmission of the virus can occur before clinical signs are expressed. Characteristic cytoplasmic inclusion bodies (Negri bodies) found in many neurons aid rapid laboratory diagnosis. Synonym(s): hydrophobia [L. rage, fury, fr. rabio, to rave, to be mad]

rabies

(rā′bēz)n. An acute, infectious, usually fatal viral disease of the central nervous system that is transmitted by the bite of infected animals and occurs in many mammals, including dogs, cats, raccoons, and bats.

ra′bi·et′ic (-ĕt′ĭk) adj.

rabies

A fatal infection rabiesvirus which follows 'injection' by an animal bite; the virion crosses the neuromuscular junction and infects nerves, spreading centripetally into the CNS and centrifugally into the salivary glands of mammals Epidemiology Human rabies is rare 1 to 2 cases/year in US; internationally, 33,000 people die/yr from rabies in Asia, Africa Clinical 18-60 day incubation, followed by nonspecific Sx–eg, fever, headache, N&V, numbness at site of exposure, and early neurologic signs–anxiety, restlessness, depression; acute neurologic phase is characterized by agitation, confusion, delirium hydrophobia, laryngeal spasms, paralysis, complications Vaccination VRG vaccine. See Negri bodies. Cf Pseudo-rabies.

ra·bies

(rā'bēz) Highly fatal infectious disease transmitted by the bite of infected animals, including dogs, cats, skunks, wolves, foxes, raccoons, and bats, and caused by a neurotropic lyssavirus that replicates in the central nervous system and the salivary glands. The symptoms are excitement, aggressiveness, and madness, followed by paralysis and death. Characteristic cytoplasmic inclusion bodies (Negri bodies) found in many of the neurons are an aid to rapid laboratory diagnosis.
Synonym(s): hydrophobia.

Rabies

A nervous system disease that affects many different animals. Rabies is a brain inflammation (encephalitis) caused by a lyssavirus, a member of the rhabdovirus family, that enters the nervous system at the site of a bite by a rabid animal. The time taken for the virus to reach the brain and cause the disease varies with the distance of the bite from the brain, and may be from 10 days to 3 or 4 months. Rabies starts with fever, headache, neck stiffness, anxiety and disorientation. Soon there is acute fear of swallowing because of violent spasms of the throat and diaphragm causing gagging, choking and extreme panic. Seizures, delusions and hallucinations then occur, followed by coma and death, usually within a week of the start of the severe symptoms. Careful cleaning of bites and the use of human antirabies globulin and rabies vaccine can prevent the disease. There is no specific treatment for the established encephalitis. Also known as hydrophobia on account of a principal symptom.

rabies

an ACUTE viral disease of the nervous system in many mammals, particularly man, dogs, cattle and foxes, resulting in degeneration of the spinal cord and brain, leading to death. Entry of the virus is usually by a wound or skin abrasion caused by a rabid animal. The incubation period is usually 3–8 weeks, the first signs being increased muscle tone and extreme difficulty in swallowing. The spasmodic contractions of the throat muscles that cause swallowing may become extremely painful and contraction may even be triggered by the sight of water. Thus individuals are described as hydrophobic. Despite recent advances, infected individuals must be vaccinated in the first few days after infection for effective treatment.

ra·bies

(rā'bēz) Highly fatal infectious disease that may affect all species of warm-blooded animals, including humans; transmitted by the bite of infected animals and caused by a neurotropic species of Lyssavirus.
Synonym(s): hydrophobia.

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Synonyms for rabies

noun an acute viral disease of the nervous system of warm-blooded animals (usually transmitted by the bite of a rabid animal)

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