Saturday, October 29, 2011

What is Rabies?

Rabies (pronounced /ˈreɪbiːz/. From Latin: rabies, "madness") is a viral disease that causes acute encephalitis (inflammation of the brain) in warm-blooded animals.[1] It is zoonotic (i.e., transmitted by animals), most commonly by a bite from an infected animal. For a human, rabies is almost invariably fatal if post-exposure 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.[2] Once the rabies virus reaches the central nervous system and symptoms begin to show, the infection is effectively 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.[1] Finally, the patient may experience periods of mania and lethargy, eventually leading to coma. The primary cause of death is usually respiratory insufficiency.[2] Worldwide, roughly 97% of rabies cases come from dog bites.[3] In the United States, however, animal control and vaccination programs have effectively eliminated domestic dogs as reservoirs of rabies.[4] In several countries, including Australia, Japan, and the United Kingdom, rabies carried by animals that live on the ground has been eradicated entirely.[5][6] Concerns exist about airborne and mixed-habitat animals including bats. A small number of bats of three species in the UK and in some other countries have been found to have European Bat Lyssavirus 1 and European Bat Lyssavirus 2.[citation needed] The symptoms of these viruses are similar to those of rabies and so the viruses are both known as bat rabies.[citation needed]
The economic impact is also substantial, as rabies is a significant cause of death of livestock in some countries

Tuesday, October 25, 2011

Sighns and symptoms


The period between infection and the first flu-like symptoms is normally two to twelve weeks, but can be as long as two years. Soon after, the symptoms expand to slight or partial paralysis, cerebral dysfunction, anxiety, insomnia, confusion, agitation, abnormal behavior, paranoia, terror, hallucinations, progressing to delirium.[2][7] The production of large quantities of saliva and tears coupled with an inability to speak or swallow are typical during the later stages of the disease; this can result in hydrophobia, in which the patient has difficulty swallowing because the throat and jaw become slowly paralyzed, shows panic when presented with liquids to drink, and cannot quench his or her thirst.
Death almost invariably results two to ten days after first symptoms. In 2005, the first patient was treated with the Milwaukee protocol,[8] and Jeanna Giese became the first person ever recorded to survive rabies without receiving successful post-exposure prophylaxis. An intention to treat analysis has since found that this protocol has a survival rate of about 8%.[9] The results of this study are, however, under serious contention and clinical rabies should still be regarded as incurable at present