Clinical Overview of Rabies

Overview

Rabies is a fatal but preventable viral disease, which can spread to people and pets through bites and scratches from an infected animal. Rabies can cause severe disease and death if urgent medical care is not sought after a rabies exposure. The virus is fatal if rabies-related medical care, called postexposure prophylaxis or PEP, is not started before symptoms begin to show.

Rabies is rare in people in the United States, with only 1 to 3 cases reported each year. However, each year about 60,000 Americans receive PEP following an exposure.

Who is at risk

There have been no confirmed instances of human-to-human transmission of rabies virus aside from those attributable to organ and tissue transplantation. Rabies virus is transmitted through direct contact with infectious tissue or fluids. Rabies virus is not transmitted through contaminated objects or materials such as clothes or bedding.

Healthcare workers providing care to patients with suspected or confirmed rabies should protect themselves by using standard precautions. Healthcare workers caring for patients with rabies do not pose a risk to their families or community.

Exposure risks

People and pets can be exposed to rabies through bites and scratches from animals infected with rabies. In the U.S., rabies is mostly found in wild animals like bats, raccoons, skunks, and foxes. But in many other countries, dogs are still carriers of rabies.

It's crucial to inquire about recent contact with wild animals, especially if the patient has been scratched or bitten. Also, ask about recent travel to areas where rabies in dogs is prevalent.

How it spreads

Rabies is spread when an infected animal, usually wild, bites or scratches other animals or people. The virus is usually carried in saliva or mucus and spreads through broken skin.

Signs and symptoms

After a rabies exposure, the rabies virus must travel to the brain before it can cause symptoms. This time between exposure and the appearance of symptoms is the incubation period, and it may last for weeks to months.

The first symptoms of rabies may be like the flu, including weakness or discomfort, fever, or headache. There also may be discomfort, prickling, or an itching sensation at the site of the bite. These symptoms may last for several days. Usually, severe disease appears within two weeks of the first symptoms, when the rabies virus causes brain dysfunction. Common signs include anxiety, confusion, agitation, and hallucinations.

Once clinical signs of rabies appear, the disease is nearly always fatal, and treatment is typically supportive.

Assessing a patient for suspected rabies exposure

Most rabies exposures require medical attention quickly, but they do not require an immediate trip to the emergency room unless the wound needs immediate medical attention. A patient should be immediately assessed for rabies-related care in the following cases:

• They had direct contact with bats unless a bite or scratch can be definitively ruled out.
• They had exposure to certain high-risk animals, which typically include bats, raccoons, skunks, foxes, and mongoose.
• They had severe exposures, such as multiple bite wounds or exposures to the head and neck.
• They are a young child.

When assessing the need for PEP in a patient with a suspected exposure, the following should be considered:

• Geographic location: Bats are a risk for rabies in every state besides Hawaii. Other high-risk animals are found in specific geographic areas of the U.S. In many countries outside of the U.S., dogs present the highest rabies risk. Consult your health department for more information on geographic rabies risk.
• Type of animal: All mammals are susceptible to rabies, however certain species are at higher risk to transmit the virus to people. These include bats, raccoons, skunks, foxes, and mongoose.
• Behavior of the animal: Rabies causes behavioral changes in animals that may not be obvious until several days after they become infectious. Unprovoked bite or scratches, and signs of apparent illness are often associated with rabid animals.

A risk assessment should always be conducted by a health official familiar with rabies. If you need assistance in conducting a rabies risk assessment, contact your state or local health department.

Rabies postexposure prophylaxis (PEP)

For people who have never had a rabies vaccine, rabies PEP consists of wound washing, a dose of human rabies immune globulin (HRIG), and a rabies vaccine given at the time of the first medical visit. Then, it includes a dose of vaccine given again on days 3, 7, and 14 after the first dose.

Pregnancy is not a contraindication for rabies PEP and exposure to rabies or a rabies diagnosis in the mother does not require pregnancy termination. More information on PEP can be found here.