Ebola virus disease (EVD ) or Ebola hemorrhagic fever (EHF) is the human disease caused by the Ebola virus . Symptoms typically start two days to three weeks after contracting the virus, with a fever , sore throat, muscle pains, and headaches . Typically nausea , vomiting, and diarrhea follow, along with decreased functioning of the liver and kidneys. At this point, some people begin to have bleeding problems. [1] The virus may be acquired upon contact with blood or bodily fluids of an infected animal (commonly monkeys or fruit bats ).[1] Spread through the air has not been documented in the natural environment. [2] Fruit bats are believed to carry and spread the virus without being affected. Once human infection occurs, the disease may spread between people as well. Male survivors may be able to transmit the disease via semen for nearly two months. In order to make the diagnosis, typically other diseases with similar symptoms such as malaria , cholera and other viral hemorrhagic fevers are first excluded. To confirm the diagnosis blood samples are tested for viral antibodies , viral RNA, or the virus itself. [1] Prevention includes decreasing the spread of disease from infected monkeys and pigs to humans. This may be done by checking such animals for infection and killing and properly disposing of the bodies if the disease is discovered. Properly cooking meat and wearing protective clothing when handling meat may also be helpful, as are wearing protective clothing and washing hands when around a person with the disease. Samples of bodily fluids and tissues from people with the disease should be handled with special caution.[1] There is no specific treatment for the disease; efforts to help persons who are infected include giving either oral rehydration therapy (slightly sweet and salty water to drink) or intravenous fluids.[1] The disease has high mortality rate: often killing between 50% and 90% of those infected with the virus. [1][3] EVD was first identified in Sudan and the Democratic Republic of the Congo. The disease typically occurs in outbreaks in tropical regions of Sub-Saharan Africa.[1] From 1976 (when it was first identified) through 2013, fewer than 1,000 people per year have been infected. [1][4] The largest outbreak to date is the ongoing 2014 West Africa Ebola outbreak , which is affecting Guinea , Sierra Leone, Liberia and Nigeria . [5][6] As of August 2014 more than 1750 suspected cases have been reported. [7] Efforts are ongoing to develop a vaccine; however, none yet exists.[1] Signs and symptoms Symptoms of Ebola. [8] Signs and symptoms of Ebola usually begin suddenly with a flu- like stage characterized by fatigue, fever, headaches, and joint, muscle, and abdominal pain. [9] [10] Vomiting, diarrhea and loss of appetite are also common. [10] Less common symptoms include the following: sore throat, chest pain, hiccups, shortness of breath and trouble swallowing .[10] The average time between contracting the infection and the start of symptoms is 8 to 10 days, but it can vary between 2 and 21 days. [10] Skin manifestations may include a maculopapular rash (in about 50% of cases). [11] Early symptoms of EVD may be similar to those of malaria, dengue fever , or other tropical fevers, before the disease progresses to the bleeding phase.[9] All people infected show some symptoms of circulatory system involvement, including impaired blood clotting. [11] In 40–50% of cases, bleeding from puncture sites and mucous membranes (e.g. gastrointestinal tract, nose , vagina and gums ) has been reported. [12] In the bleeding phase, which typically starts five days after first symptoms[13] , internal and subcutaneous bleeding may present itself through reddening of the eyes and bloody vomit.[9] Bleeding into the skin may create petechiae, purpura, ecchymoses, and hematomas (especially around needle injection sites). Types of bleeding known to occur with Ebola virus disease include vomiting blood, coughing it up or blood in the stool . Heavy bleeding is rare and is usually confined to the gastrointestinal tract. [11][14] In general, the development of bleeding symptoms often indicates a worse prognosis and this blood loss can result in death.[15] Causes Main article: Ebolavirus Life cycles of the Ebolavirus EVD is caused by four of five viruses classified in the genus Ebolavirus, family Filoviridae , order Mononegavirales. These four viruses are Bundibugyo virus (BDBV), Ebola virus (EBOV), Sudan virus (SUDV), Taï Forest virus (TAFV). The fifth virus, Reston virus (RESTV), is not thought to be disease-causing in humans. During an outbreak, those at highest risk are health care workers and close contacts of those with the infection. [16]
Posted on: Sun, 10 Aug 2014 05:59:26 +0000
Trending Topics
Recently Viewed Topics
© 2015