Rabies
By: Janna • Essay • 1,003 Words • May 26, 2010 • 1,536 Views
Rabies
Rabies is caused by the rabies virus which is an infectious disease that destroys the nerve cells of the brain and cause death. It is a viral zoonotic neuroinvasive disease that causes acute encephalitis or inflammation of the brain in mammals. Humans and most mammals develop this disease (HE-DC)
Rabies is a Latin word, meaning rage or fury. It probably receive this name because infected animals often become excited and attack any object or animal in their way. Rabies is also referred to hydrophobia which mean fear of water, this is one of many symptoms that infected animals receive (HE-DC).
Rabies is caused by a virus that lives in the saliva of a host. Most mammals can carry the rabies virus. If the host bites another animal or human being, or if some of the saliva enters an open wound, the victim may contract the rabies virus. Humans and some animals have devolved the deadly disease in caves containing millions of bats, by just breathing in the air. The virus can enter mucous membranes, such as those lining the nose, but the virus cannot invade unbroken skin. Many people associate rabies with dogs but in actuality cats are infected more (HE-DC).
The virus has a bullet-like shape with a length of about 180 nm and a cross-sectional diameter of about 75 nm. One end is rounded or conical and the other end is planar or concave. The lipoprotein envelope carries knob-like spikes composed of Glycoprotein. The spikes do not cover the flat end of the virus particle. Beneath the envelope is the membrane or matrix protein layer which may be invaginated at the flat end. The core of the virus particle consists of helically arranged ribonucleoprotein. The genome is unsegmented linear antisense RNA. Also present in the nucleocapsid are RNA dependent RNA transcriptase and some structural proteins (MDC).
When the virus enters the body, it travels along nerves to the spine and brain, producing inflammation. Once symptoms appear, death is inevitable with out proper treatment. The symptoms develop about 10 days to 7 months after exposure.
There are different symptoms for humans then animals. Humans first stage of symptoms are pain, burning or numbness of the site of infection (Rabies Symptoms). The second stage of symptoms are headaches and is unable to sleep. Other complaints are fevers, chills, fatigue, muscle aches, and irritability may accompany these complaints. Early on, these complaints may seem like any virus, except for the shooting sensations from the bite site (Harrigan). Also muscle spasms make the throat feel full, and swallowing becomes difficult. Sometimes the sight of water creates such painful throat contraction that drinking is dreaded this it called hydrophobia, also some people may experience the fear of air which is called aerophobia (Rabies Symptoms).Signs of nervous system damage appear, hyperactivity and hypersensitivity, disorientation, hallucinations, seizures, and paralysis. Death may be sudden, due to cardiac or respiratory arrest, or follow a period of coma that can last for months with the aid of life-support measures (HE-DC). And in later stages patients may have convulsion which is uncontrollable shaking: a violent shaking of the body or limbs caused by uncontrollable muscle contractions. But after a day or two the patient lapses into a quiet period, which progresses to unconsciousness and, finally, death. The disease lasts from 2 to 12 days. The symptoms of animals are that during the period of excitation the animals may travel great distances (MDC). It may become overly aggressive