Signs and symptoms: The period between infection and the first symptoms (incubation period) is typically one to three months in humans.[23] This period may be as short as four days or longer than six years, depending on the location and severity of the wound and the amount of virus introduced.[23] Initial symptoms of rabies are often nonspecific such as fever and headache.[23] As rabies progresses and causes inflammation of the brain and meninges, symptoms can include slight or partial paralysis, anxiety, insomnia, confusion, agitation, abnormal behavior, paranoia, terror, and hallucinations.[10][23] The person may also have fear of water.[1]