Rabies

Rabies (/ˈreɪbiːz/. From Latin: rabies, "madness") is a viral disease that causes acute encephalitis in warm-blooded animals. The disease is zoonotic, meaning it can be transmitted from one species to another, such as from dogs to humans, commonly by a bite from an infected animal. For a human, rabies is almost invariably fatal if postexposure prophylaxis is not administered prior to the onset of severe symptoms. The rabies virus infects the central nervous system, ultimately causing disease in the brain and death.

The rabies virus travels to the brain by following the peripheral nerves. The incubation period of the disease is usually a few months in humans, depending on the distance the virus must travel to reach the central nervous system. Once the rabies virus reaches the central nervous system and symptoms begin to show, the infection is virtually untreatable and usually fatal within days.

Early-stage symptoms of rabies are malaise, headache and fever, progressing to acute pain, violent movements, uncontrolled excitement, depression, and hydrophobia. Finally, the patient may experience periods of mania and lethargy, eventually leading to coma. The primary cause of death is usually respiratory insufficiency.

Rabies causes about 55,000 human deaths annually worldwide. 95% of human deaths due to rabies occur in Asia and Africa. Roughly 97% of human rabies cases result from dog bites. In the US, animal control and vaccination programs have effectively eliminated domestic dogs as reservoirs of rabies. In several countries, including Australia and Japan, rabies carried by terrestrial animals has been eliminated entirely. While rabies had once been eradicated in the United Kingdom, infected bats have recently been found in Scotland.