It is believed but not proven that rabies appeared in North America from European explorers traveling with infected animals, according to Wildwood Survival. Writings about rabies date back to ancient Mesopotamia and Egypt.
A person or animal can contract rabies by coming into contact with infected saliva, eating rabid meat, breathing heavily infected air, and inheriting it from a parent, Wildwood Survival states. Unlike most viruses that travel through the bloodstream, rabies travels through nerve cells. Once in the body, it spreads from nerve cells to the spinal column and from there to the brain and the rest of the body. Any mammal, including humans, can contract any kind of rabies if they come into contact with it.
Early symptoms of rabies include general weakness, discomfort, headache and fever, according to the Centers for Disease Control and Prevention. If there is a bite, there may be itching and agitation around the site. These symptoms progress to cerebral dysfunction, anxiety, confusion, agitation, delirium, hallucinations and insomnia. Once clinical rabies symptoms appear, the disease is almost always fatal, the CDC states, adding that here are fewer than 10 documented cases of human survival. Disease prevention includes an injection of an antibody through injections of human immune globulin and the rabies vaccine.