| Rabies is an acute infectious disease of the central nervous system, which affects all warm-blooded animals, including humans. It is caused by an RNA virus belonging to the rhabdovirus group. 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, mongoose, 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.
P "revention" REVENTION. All warm-blooded family pets-including 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 avoid water. Actually, they do not do so because of fear, 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 his throat. Usually, a dog with something in his throat tries to remove it himself, but a rabid dog will not. Eventually all of the rabid animal's muscles become paralyzed and it dies.
T "reatment" REATMENT. 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 go to a physician immediately. If at all possible, steps should be taken to find out if the biting animal has rabies. The animal should be confined 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. There are times when the biting animal cannot be caught for observation. If so, 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 very 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 rabies immune globulin (HRIG) and anti-rabies serum, equine (ARS). Allergic reactions to HRIG are rare, and it is the preferred agent for this reason. A few patients experience severe anaphylaxis while others develop serum sickness in response to administration of ARS; hence, it is given only when HRIG is not available.
Active immunity to rabies can be conferred by administration of duck embryo vaccine (DEV). 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 human diploid cell vaccine (HDCV). 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. What are the symptoms of rabies?
The first symptoms of rabies are fever, headache, malaise, and vomiting. Inability to swallow, disorientation, and coma follow. There is no cure for rabies once symptoms appear.
How is rabies transmitted?
Rabies is transmitted in the saliva of an infected animal by a bite or a scratch. Rabies is most common in skunks, raccoons, foxes, and bats. These animals can infect domestic cats, dogs, and live stock. Rabies is rare in small rodents such as beavers, chipmunks, squirrels, rats, mice, hamsters, gerbils, guinea pigs, and rabbits. Bats can transmit rabies through their droppings in close confines such as caves.
How can rabies be avoided?
To prevent the spread of rabies:
| • | All domestic cats and dogs, as well as livestock, should have up-to-date rabies vaccinations. Check with a veterinarian about current recommendations for rabies vaccine and periodic boosters. | | • | Teach children not to approach or play with wild animals, even baby animals. | What should I do if I am exposed to rabies?
If you or your child are bitten or scratched by an animal or have the possibility of any rabies exposure:
| • | Immediately wash the wound thoroughly with soap and water. | | • | Call your doctor or emergency department for advice. | | • | Learn all you can about the animal and how it attacked. | Be sure to check out this site too!! - Bats, Humans and Rabies....(a must see) |
