Rabies: A-to-Z Guide from Diagnosis to Treatment to Prevention

Child playing with a dog in the wilderness. Dogs need rabies vaccinations.Introduction to rabies:

The vampire myth may have been inspired by the reality of a severe rabies epidemic in Hungary from 1721 to1728. Rabies may be transmitted by the bite of infected bats, wolves, other animals, or people. People with rabies are extra-sensitive to light, water, strong odors (garlic), and may refuse to look at their own reflections. Usually, the facial expression is grim, but confronted with any of these things, the person with rabies may have an involuntary spasm of the facial muscles, baring the teeth and frothing bloody fluid at the mouth. Rabies also changes the sleep-wake cycle and may cause hypersexuality.

What is it?

Rabies is a horrible viral illness that attacks the brain. It is fatal unless rabies shots are given promptly, before any symptoms appear.

Who gets it?

Rabies is transmitted through the saliva of infected, warm-blooded animals. Worldwide, dogs are the most common source of it. Rabies vaccination of pets has made dogs an uncommon source in the United States, where skunks, raccoons, foxes, coyotes, and bats are the main source of rabies infections.  Contrary to popular belief, it is quite rare for rabies to infect small rodents such as squirrels, hamsters, guinea pigs, rats, and mice or for lagomorphs such as rabbits and hares (RedBook 2010).  For information specific to a particular region of the country or world, the local department of public health is often able to offer epidemiologic information on rabies infection of local wild and domestic animals.

Most people who get it have been bitten by an infected animal, but close contact with an infected bat will sometimes cause infection without a bite.

Some islands, such as Australia, the United Kingdom, and Hawaii, are generally free of rabies.

Children get it far more often than adults.

What are the symptoms?

Rabies usually begins with several days of non-specific symptoms such as headache, fever, vomiting, loss of appetite, or depression. The bite wound may hurt, itch, or feel strange.

Hydrophobia, or fear of water, is a classic symptom that may appear next. At first, people have difficulty swallowing liquids. Later, just the sight of water can be terrifying. Eating solids can be quite painful.

People with rabies often become anxious and agitated. Seizures are common. Some develop paralysis or intense muscle spasms.

Is it contagious?

People with rabies do have the virus in their saliva, beginning about a week before the symptoms develop. Nevertheless, other animals are almost always the source of human infections. Rabies has been spread by corneal transplants from someone who died before a diagnosis was made.

How long does it last?

Symptoms usually begin 1 to 6 months after a bite from an infected animal. They can appear as quickly as a week or so after the bite, or take years to develop.

Once symptoms appear, death occurs within 3 or 4 weeks.

How is it diagnosed?

The diagnosis is often made based on the characteristic symptoms occurring after exposure to an animal that might carry rabies. Identifying the virus on animal autopsy can support the diagnosis. Sometimes the virus can be detected in the infected person prior to death.

Rabies is sometimes confused with tetanus or encephalitis.

How is it treated?

Supportive care is given to people with rabies.

How can it be prevented?

Preventing rabies depends on vaccinating pets, avoiding contact with infected animals, and promptly giving the rabies vaccine to people who have had high-risk contact with an animal presumed to have been infected.

Animal bites should be flushed vigorously with soap and water, or an antiseptic and water, for at least 10 minutes. Any dog, cat, or ferret that bites a child should be observed by a veterinarian for 10 days, and immediate steps should be taken if the animal shows signs of illness or is not available for observation. Skunks, raccoons, foxes, and bats should be considered infected unless proven otherwise. In addition, any person bit by an animal should immediately speak with his or her doctor about the need for vaccinations to prevent infection.

Related concepts:

Hydrophobia

Dr. Alan Greene

Dr. Greene is a practicing physician, author, national and international TEDx speaker, and global health advocate. He is a graduate of Princeton University and University of California San Francisco.

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