Rabies is a fatal nervous system infection that is caused by the rabies virus.

What is going on in the body?

The rabies virus is present worldwide. It can be spread to humans by many different animals. In the US, animal bites from wild animals, such as raccoons, skunks and bats, usually pass the virus on to people. In less developed countries where cats and dogs are not vaccinated against rabies, dog bites are the most common source of rabies.

The rabies virus lives in the saliva of infected animals. It is spread to another animal or a person through a bite or through licking an open wound. In rare cases, people may have breathed in the virus while visiting a heavily infected area, such as a bat cave. In some recent cases of human rabies, there has been no known contact with a bat or other potentially infected animal. This suggests that very little physical contact with an infected animal may be needed to catch the virus in some cases.

What are the causes and risks of the infection?

The rabies virus causes the infection. Unless people exposed to the virus are treated promptly, death is almost certain. Treatment rarely helps after symptoms develop.