The incubation period for rabies is typically 2-3 months; however, this could vary from 5 days to several years. Initial symptoms of rabies are usually non-specific. Often times there will be fever, pain or unusual or unexplained tingling, and pricking or burning sensation (paraesthesia) at the wound site.
As the virus spreads through the central nervous system, progressive, fatal inflammation of the brain and spinal cord develops.
There are two forms of rabies: furious form and the paralytic form.
- Furious rabies accounts for approximately 70% of the total number of human cases and will manifest as signs of hyperactivity, excited behavior, hydrophobia and sometimes aerophobia. After a few days, death occurs by cardio-respiratory arrest.
- Paralytic rabies (or dumb rabies) accounts for approximately 30% of the total number of human cases. This form of rabies runs a less dramatic but longer course than the furious form. The muscles gradually become paralyzed, starting at the site of the bite or scratch. A coma slowly develops and eventually death occurs. The paralytic form of rabies is often misdiagnosed, contributing to the underreporting of the disease.