Pam Nardone, age 11, of East Brunswick, N.J., for her question:

WHAT CAUSES RABIES?

Rabies is an infectious disease that destroys the nerve cells of part of the brain and also almost always brings death. Humans and all other warm blooded animals are susceptible to the disease of rabies.

Rabies is caused by a virus that lives in the saliva of the carrier. And, unfortunately, almost all mammals can carry the rabies virus. If the carrier or host bites another animal or a person, or if some of its saliva enters an open wound, the victim may get rabies.

Dogs, cats and wild animals are common sources of infection for people.

When the virus goes into a person's body, it can travel along nerves to the spine and brain, producing inflammation. The symptoms may develop 10 days to seven months after exposure.