Rabies

Definition

Rabies is an often fatal viral infection primarily spread by infected animals.

Causes

Rabies is spread by infected saliva that enters the body through a bite or broken skin. The virus travels from the wound to the brain, where it causes swelling, called inflammation. This inflammation results in the symptoms of the disease. Most rabies deaths occur in children.

The actual time between infection and when you get sick (called the "incubation period") ranges from 10 days - 7 years. The average incubation period is 3 - 7 weeks.

In the past, human cases in the U.S. usually resulted from a dog bite, but recently, more cases of human rabies have been linked to raccoons or bats. Although dog bites are a common cause of rabies in developing countries, there have been no reports of rabies caused by dog bites in the U.S. for a number of years due to widespread animal vaccination.

Other wild animals that can spread the rabies virus include:

• Bats
• Foxes
• Raccoons
• Skunks

Very rarely, rabies has been transmitted without an actual bite. This is believed to have been caused by infected saliva that has gotten into the air.

The United Kingdom had once completely eradicated rabies, but recently, rabies-infected bats have been found in Scotland.

References

Marx J. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 5th ed. St. Louis, Mo: Mosby; 2002:1837-1838.

Stantic-Pavlinic M. Public health concerns in bat rabies across Europe. Euro Surveill. 2005 Nov 1;10(11) .

Brookes SM, Aegerter JN, Smith GC. European bat lyssavirus in Scottish bats. Emerg Infect Dis. 2005 Apr;11(4):572-8.

Cohen J, Powderly WG. Infectious Diseases. 2nd ed. New York, NY: Elsevier; 2004:1503-1506.

McLellan SL. Vaccine special issues: yellow fever, rabies, and Japanese encephalitis. Clin Fam Pract. 2005;7:697-716.

Marx J. Rosen's Emergency Medicine: Concepts and Clinical Practice. 6th ed. St. Louis, Mo: Mosby; 2006.