Rabies is a zoonotic viral disease that causes acute and severe encephalitis in humans and other mammals. It was historically referred to as hydrophobia because most of its victims panic when offered liquids to drink as a result of uncontrollable, painful spasms in their throat muscles when they swallow. Early symptoms can include fever and abnormal sensations at the site of exposure, which are followed by nausea, vomiting, violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion or loss of consciousness. Once symptoms appear, the result is virtually always death. The time period between contracting the disease and the start of symptoms is usually one to three months but can vary from less than one week to more than one year. The time depends on the distance the virus must travel along peripheral nerves to reach the central nervous system.