Rabies is an infection caused by a virus. It affects the brain and spinal cord (central nervous system) of mammals, including humans. It is nearly always deadly if not treated before symptoms begin.
Animals that are infected with rabies—rabid animals—can spread the disease through their saliva or through brain tissue.
It is rare for people in Canada or the United States to get rabies. It is more common in developing nations.
People usually get rabies when a rabid animal bites them. People in Canada and the U.S. are most likely to get rabies from bats.footnote 1 People in many other countries are most likely to get rabies from dog bites.footnote 2, footnote 3
Bats, raccoons, skunks, foxes, and coyotes are the animals most likely to have rabies in Canada and the U.S. Small mammals such as mice and squirrels almost never have rabies.
Sometimes the rabies virus can spread to pets, such as dogs, cats, and ferrets. But household pets rarely get rabies, because most of them get rabies vaccines. Pets that stay indoors are very unlikely to get rabies.
It's possible to get rabies even when you don't see an animal bite. For example, bat bites or scratches may be so small that you don't notice them. If you or your children come in direct contact with a bat, or if you find a bat in a closed room with a sleeping person, call your doctor right away.
Signs of rabies in animals may include drooling, foaming at the mouth, or paralysis. A pet with rabies also may behave differently than usual, such as acting shy when the pet usually is friendly. A wild animal with rabies may have no fear of humans.
Rabies in humans begins with symptoms such as fever, cough, or sore throat. Later, symptoms become more serious and can include restlessness, hallucinations, and seizures. The final stage is coma and death.
If you think you've been exposed to the rabies virus, it's very important to get medical care before symptoms begin. If symptoms appear, it's too late for a cure, and the infection will probably lead to death. The time from exposure to the virus until symptoms appear usually is 2 to 3 months. In rare cases, it may be shorter or much longer. The time before symptoms start depends on the location of the bite. For example, a bite on the face will cause symptoms much sooner than a bite on a foot.
The treatment for someone who has been exposed to rabies is a series of shots known as post-exposure prophylaxis (PEP). These shots help the body's immune system destroy the disease in its early stages. Getting PEP before symptoms appear usually prevents infection, and you are likely to recover.
In Canada and the U.S., PEP has two parts, usually given at the same time:
Some vaccines that aren't approved for use in Canada or the U.S. are used in developing countries. The World Health Organization (WHO) approves of these vaccines.footnote 4 But they may cause worse reactions than newer vaccines. If you are exposed to rabies outside of Canada or the U.S. and have any choice, request HDCV (human diploid cell vaccine), RVA (rabies vaccine, adsorbed), or PCEC (purified chick embryo cell culture). If these aren't available, it is better to accept one of the other vaccines than to get no vaccine at all. As soon as you can return home, ask your doctor about whether you should get any more vaccines.
First, wash the animal bite, scratch, or open sore with soap and water. Then call your doctor, your local health unit or Health Link at 811 right away. They can advise you on what to do next.
If you've been bitten by or exposed to an animal at low risk for having rabies, such as a pet, the animal will be captured and watched for signs of rabies. If there's a chance that the animal is rabid, you will start getting shots right away.
If you've been bitten by or exposed to an animal at high risk for having rabies, you will start getting shots right away. If possible, the animal will be watched for signs of rabies or will be killed for testing. If it turns out that the animal doesn't have rabies, you can stop the shots.
If an animal shows signs of rabies but can't be captured for testing, it often is assumed to be rabid.
To avoid contact with the rabies virus:
Preventive rabies vaccination may be recommended if you are at high risk of exposure because of your work or hobbies. It may also be recommended if you plan to travel in areas where rabies is a risk, such as parts of Asia, Africa, and Central and South America. Contact your doctor or local public health department for more information.
Plotkin SA, et al. (2009). Rhabdoviridae: Rabies virus. In RD Feigin et al., eds., Feigin and Cherry's Textbook of Pediatrics Infectious Diseases, 6th ed., vol. 2, pp. 2494–2511. Philadelphia: Saunders Elsevier.
Centers for Disease Control and Prevention (2008). Human rabies prevention—United States 2008. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR, 57(Early Release): 1–28. Available online: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5703a1.htm.
Rupprecht CE, Givvons RV (2004). Prophylaxis against rabies. New England Journal of Medicine, 351: 2626–2635.
World Health Organization (2016). Rabies fact sheet. World Health Organization. http://www.who.int/mediacentre/factsheets/fs099/en. Accessed April 6, 2016.
Current as ofJuly 30, 2018
Author: Healthwise StaffMedical Review: E. Gregory Thompson, MD - Internal MedicineAnne C. Poinier, MD - Internal MedicineAdam Husney, MD - Family MedicineKathleen Romito, MD - Family MedicineElizabeth T. Russo, MD - Internal MedicineW. David Colby IV, MSc, MD, FRCPC - Infectious DiseaseMartin J. Gabica, MD - Family Medicine
Current as of: July 30, 2018
E. Gregory Thompson, MD - Internal Medicine & Anne C. Poinier, MD - Internal Medicine & Adam Husney, MD - Family Medicine & Kathleen Romito, MD - Family Medicine & Elizabeth T. Russo, MD - Internal Medicine & W. David Colby IV, MSc, MD, FRCPC - Infectious Disease & Martin J. Gabica, MD - Family Medicine
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