What is rabies disease, and how is it spread?
Rabies virus is common among wild animals, but usually is only a threat to humans when an infected animal bites a human. The virus enters the body, attaches to the distant nerve endings, and follows the connection of nerves to the brain. It may take as little as six days or as long as six years for the virus to reach the brain, but usually the incubation phase is a month or two. A preliminary illness follows in which the patient has a headache, fever, fatigue, and a loss of appetite. The rabies-infected person may have intermittent spurts of irritability, aggression, viciousness, and hyper-reactivity to light, touch, or sound. Attempts to eat or drink-and, eventually, the mere sight of liquids-may produce painful throat spasms, causing the patient to develop a fear of water (hydrophobia). Increased saliva output and the inability to swallow give the patient the appearance of “foaming at the mouth.” More central nervous symptoms, such as convulsions, may appear before the next phase, in
