rabies

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 Pasteur 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.

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rabies

Acute, usually fatal infectious disease of warm-blooded animals that attacks the central nervous system. It is spread by contact with an infected animal's saliva, usually from a bite. The rhabdovirus that causes it spreads along nerve tissue from the wound to the brain. Symptoms usually appear four to six weeks later, often beginning with irritability and aggressiveness. Wild animals lose their fear of humans and are easily provoked to bite, as are pets. Depression and paralysis soon follow. Death usually comes three to five days after symptoms begin. In humans, death can result from a seizure in the early phase even before symptoms of central nervous system depression develop. One name for rabies, hydrophobia (“fear of water”), comes from painful throat contraction on trying to swallow. If not treated in time (within a day or two) with a serum containing antibodies and then a series of vaccinations, rabies in humans is almost always fatal. Immediate cleansing of animal bites with soap and water can remove much of the virus.

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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

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rabies [′rā·bēz]

(veterinary medicine)

An acute, encephalitic viral infection transmitted to humans by the bite of a rabid animal. Also known as hydrophobia.

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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