Rabies, << RAY beez, >> is an infectious disease that destroys the nerve cells of part of the brain and almost always causes death. Human beings and most other mammals can get the disease. The word rabies is Latin for rage or fury. The disease probably received its name because infected animals often become excited and attack any object or animal in their way. Because one of the symptoms of rabies is an inability by the infected animal to swallow water, the disease is sometimes called hydrophobia, which means fear of water.
Cause.
Rabies is caused by a virus known as a rhabdovirus. Most mammals can carry this virus, which usually lives in the nerve cells and glands of the host (carrier). The rabies virus can be carried in the salivary glands for long periods of time. If the host bites another animal or a human being, or if some of its infected saliva enters an open wound, the victim may get rabies. Dogs, cats, and wild animals are common sources of infection for people. Research indicates that rabies virus can also enter mucous membranes, such as those lining the nose and eyes. People and other mammals can develop rabies after breathing the air in caves that house large numbers of bats, which may carry the virus.
When rabies virus enters the body, it travels along nerves to the spinal cord and up to the brain, producing inflammation. Symptoms of the disease generally develop about 10 days to 7 months after exposure.
Symptoms in human beings.
Among the first symptoms are pain, burning, or numbness at the site of the infection. The victim complains of headaches and is extremely restless. Muscle spasms make the throat feel full, and swallowing becomes difficult. Later, the patient may have convulsions. After a day or two, a quiet period can occur, which can progress to unconsciousness and, finally, death. Symptoms generally last from 2 to 12 days.
Symptoms in animals.
The development of rabies in animals follows the same pattern as in people. During the period of excitation, the animal may wander great distances. It vocalizes almost constantly, often becomes aggressive, and will attack without reason. The disease then usually progresses to paralysis of the jaw and throat muscles, followed by general paralysis and death. Some animals with rabies never show signs of excitation but only of paralysis. This form of the disease is sometimes called dumb rabies. Some animals that recover from rabies continue to carry and spread the virus.
Treatment.
The first step in treating a person bitten by any animal should be to wash the wound with soap and water. The animal should either be caged and watched for signs of rabies, or killed and its brain tissue tested for rabies virus. If either procedure indicates the presence of rabies, a doctor should begin preventive treatment at once. If the animal cannot be found, the doctor may follow such treatment as a safety measure. Standard preventive treatment in the United States consists of one injection of antirabies globulin followed by five injections of rabies vaccine. Vaccinating all dogs and cats against rabies is an important means of controlling the disease.
