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Rabies Virus

The rabies virus, an RNA virus that affects mammals (including humans), attacks the brain, causing severe inflammation and may be fatal if not treated. In nearly all cases of rabies, the virus is transmitted through the saliva of an infected animal, most often through a bite. When the rabies virus reaches the brain, it multiplies quickly and rabies symptoms begin. In humans, symptoms of the rabies virus often begin with fever, headache, and fatigue, and are usually followed by confusion, agitation, hallucination, and paralysis.

 

Rabies Virus: An Introduction

Rabies is caused by a virus that attacks the brain, causing severe inflammation (encephalopathy) and death if not treated. This virus is called the rabies virus. The rabies virus, which is an RNA virus, is part of the family of viruses called Rhabdoviruses. It appears that there are several variations of the rabies virus that are able to cause rabies.
 

Transmission of the Rabies Virus

In nearly all cases of rabies, the virus enters the body through the saliva of an infected animal, usually by a bite, but it can also be transmitted if infected saliva gets into an open wound or splashes into mucous membranes such as those in the eyes, nose, or mouth. From the saliva's point of entry, the rabies virus travels along nerve cells to the brain. It multiplies there and moves to the salivary glands. In a rabid animal, the cycle is repeated when the animal bites a person or another animal.
 

Animals and the Rabies Virus

Although all species of mammals can become infected with the rabies virus, only a few species are best able to spread the virus to other animals. These species include, but are not limited to:
 
  • Raccoons
  • Skunks
  • Foxes
  • Coyotes
  • Bats.
     
Only mammals get rabies. Birds, reptiles, amphibians, and fish do not get the disease.
 
(Click Animals With Rabies for more information.)
 

Rabies Virus: Incubation Period

When an animal is infected with the rabies virus, the virus multiplies within the body until it results in symptoms. The period between infection and the onset of symptoms is known as the incubation period. The rabies incubation period may vary from a few days to several years, but typically lasts one to three months.
 

Symptoms of the Rabies Virus

When the rabies virus reaches the brain, it multiplies quickly and rabies symptoms begin. Rabid animals may be aggressive and vicious, or lethargic and weak. In people, early rabies symptoms of fever, headache, and fatigue are usually followed by confusion, agitation, hallucination, and paralysis. Once symptoms of rabies begin, the disease is almost always fatal.
 
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Written by/reviewed by: Arthur Schoenstadt, MD
Last reviewed by: Arthur Schoenstadt, MD