EBOLA VIRUS ALL YOU WANT TO KNOW

Ebolavirusdisease(EVD) orEbolahemorrhagic fever(EHF) is the human disease caused by the ebola virus. Symptoms typically start two days to three weeks after contracting thevirus, with a fever, throat and muscle pains, and headaches. There is then typically nausea, vomiting, and diarrhea, along with decreased functioning of the liverand kidneys. At this point, some people begin to have problems with bleeding. [ 1 ] The disease is usually acquired when a person comes into contact with the blood or bodily fluidsof an infected animal such as a monkey or fruit bat. Fruit bats are believed to carry and spread theviruswithout being affected by it. Once infection of a human occurs, the disease may be spread from one person to another. Men who survive may be able to transmit the disease via their semenfor nearly two months. To make the diagnosis, typically other diseases with similar symptoms such as malaria, choleraand other viral hemorrhagic feverare first excluded. The blood may then be tested for antibodiesto thevirus, or the viral RNA, or thevirusitself, to confirm the diagnosis. [ 1 ] Prevention includes decreasing the spread of the disease from infected monkeys and pigs to humans. This may be done by checking these types of 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 is wearing protective clothing and washing hands when around a person who has 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 thevirus. Efforts to help persons who are infected include giving them either oral rehydration therapyor intravenous fluids. [ 1 ]The disease has a high mortality rate: often between 50% and 90% of those who are infected with thevirus. [ 1 ] [ 2 ]It typically occurs in outbreaks in tropical regions of Sub-Saharan Africa. [ 1 ]Between 1976, when it was first identified, and 2014, fewer than 1,000 people a year have been infected. [ 1 ] [ 3 ]The largest outbreak to date is the ongoing 2014 West Africa Ebola outbreak, which is affecting Guinea, Sierra Leone, and Liberia. The disease was first identified in the Sudanand the Democratic Republic of the Congo. Efforts are ongoing to develop a vaccine; however, none exists as of 2014. [ 1 ] Contents 1 Signs and symptoms 1.1 Hemorrhage 2 Causes 2.1 Transmission 2.2 Risk factors 2.3 Virology 3 Diagnosis 3.1 Classification 4 Prevention 4.1 Endemic zones 4.2 During outbreaks 4.3 In the laboratory 5 Treatment 5.1 Experimental therapies 6 Prognosis 7 Epidemiology 7.1 2007 to 2011 7.2 2012 outbreaks 7.3 2014 outbreak 8 History 9 Other animals 9.1 Domestic animals 10 Recent research 11 References 12 External links Signs and symptoms [ edit] Manifestation ofEbolabegins abruptly with a sudden onset of an influenza-like stage characterized by general malaise, fever with chills, sore throat, severe headache, weakness, joint pain, muscle pain, and chest pain. [ 4 ] Respiratory tractinvolvement is characterized by pharyngitiswith sore throat, cough, dyspnea, and hiccups. The central nervous systemis affected as judged by the development of severe headaches, agitation, confusion, fatigue, seizures, and sometimes coma. Cutaneous presentation may include: maculopapular rash, petechiae, purpura, ecchymoses, and hematomas(especially around needle injection sites). In general, development of hemorrhagic symptoms is indicative of a negative prognosis. However, contrary to popular belief, hemorrhage does not lead to hypovolemiaand is not the cause of death(total blood loss is low except during labor). Instead, death occurs due to multiple organ dysfunction syndrome(MODS) due to fluid redistribution, hypotension, disseminated intravascular coagulation, and focal tissue necroses. The average time between contracting the infection and the onset of symptoms is 13 days, but can be as long as 25 days. [ 5 ] Hemorrhage[ edit] All people infected show some extent of coagulopathyand impaired circulatory system symptomology. [ 6 ]Bleeding from mucous membranes and puncture sites is reported in 40–50% of cases, [ 7 ]while maculopapular rashes are evident in approximately 50% of cases. [ 6 ]Sources of bleeds include hematemesis, hemoptysis, melena, and aforementioned bleeding from mucous membranes ( gastrointestinal tract, nose, vaginaand gingiva). However diffuse bleeding (i.e. heavy) is rare; occurrence is usually exclusive to the gastrointestinal tract. [ 6 ] [ 8 ] Causes [ edit] Main article: Ebolavirus EVD is caused by four of five viruses classified in the genus Ebolavirus, family Filoviridae, order Mononegavirales: Bundibugyo virus (BDBV), Ebola virus(EBOV), Sudan virus(SUDV), Taï Forest virus(TAFV). The fifthvirus, Reston virus(RESTV), is thought not to be disease-causing in humans. Transmission[ edit] EVD is believed to occur after anebolavirusis transmitted to a human index case via contact with an infected animal's bodily fluids. Human-to-human transmission occurs via direct contact with blood or bodily fluids from an infected person (including embalmingof an infected dead person) or by contact with contaminated medical equipment, particularly needles and syringes. Medical workers who do not wear protective clothing, such as gloves and surgical masks, may also contract the disease. [ 9 ]In the past, explosive nosocomialtransmission has occurred in under-equipped African hospitals due to the reuse of needles and lack of implementation of universal precautions.[ citation needed]Aerosol transmission has not been observed during natural EVD outbreaks. [ citation needed]The potential for widespread EVD epidemicsis considered low due to the high case-fatality rate, the rapidity of demise of patients, and the often remote areas where infections occur. [ citation needed] Risk factors[ edit] [image] Bushmeatbeing prepared for cooking in Ghana, 2013. Human consumption of equatorial animals in Africa in the form of bushmeat has been linked to the transmission of diseases to people, includingEbola. [ 10 ] Between 1976 and 1998, in 30,000 mammals, birds, reptiles, amphibians, and arthropodssampled from outbreak regions, noebolaviruswas detected apart from some genetic traces found in six rodents ( Mus setulosusand Praomys) and one shrew ( Sylvisorex ollula) collected from the Central African Republic. [ 11 ] [ 12 ]Traces of EBOV were detected in the carcasses of gorillasand chimpanzees during outbreaks in 2001 and 2003, which later became the source of human infections. However, the high lethality from infection in these species makes them unlikely as a natural reservoir. [ 11 ] Plants, arthropods, and birds have also been considered as possible reservoirs; however, batsare considered the most likely candidate. [ 13 ]Bats were known to reside in the cotton factory in which the index casesfor the 1976 and 1979 outbreaks were employed, and they have also been implicated in Marburg virusinfections in 1975 and 1980. [ 11 ]Of 24 plant species and 19 vertebrate species experimentally inoculated with EBOV, only bats became infected. [ 14 ] The absence of clinical signs in these bats is characteristic of a reservoir species. In a 2002–2003 survey of 1,030 animals including 679 bats from Gabonand the Republic of the Congo, 13 fruit bats were found to contain EBOV RNA fragments. [ 15 ]As of 2005, three types of fruit bats( Hypsignathus monstrosus, Epomops franqueti, and Myonycteris torquata) have been identified as being in contact with EBOV. They are now suspected to represent the EBOV reservoir hosts. [ 16 ] [ 17 ] The existence of integrated genes of filoviruses in some genomes of small rodents, insectivorous bats, shrews, tenrecs, and marsupials indicates a history of infection with filoviruses in these groups as well. [ 18 ]However, it has to be stressed that infectious ebolaviruses have not yet been isolated from any nonhuman animal. Bats drop partially eaten fruits and pulp, then terrestrial mammals such as gorillas and duikersfeed on these fallen fruits. This chain of events forms a possible indirect means of transmission from the natural host to animal populations, which have led to research towards viral shedding in the saliva of bats. Fruit production, animal behavior, and other factors vary at different times and places that may trigger outbreaks among animal populations. [ 19 ]Transmission between natural reservoirs and humans are rare, and outbreaks are usually traceable to a single index case where an individual has handled the carcass of gorilla, chimpanzee, or duiker. [ 20 ]Fruit bats are also eaten by people in parts of West Africa where they are smoked, grilled or made into a spicy soup. [ 17 ] [ 21 ]Thevirusthen spreads person-to-person, especially within families, hospitals, and during some mortuaryrituals where contact among individuals becomes more likely. [ 22 ] Thevirushas been confirmed to be transmitted through body fluids. Transmission through oral exposure and through conjunctivaexposure is likely [ 23 ]and has been confirmed in non-human primates. [ 24 ]Filoviruses are not naturally transmitted by aerosol. They are, however, highly infectious as breathable 0.8–1.2 micrometre droplets in laboratory conditions; [ 25 ] because of this potential route of infection, these viruses have been classified as Category A biological weapons. [ 26 ] All epidemics ofEbolahave occurred in sub-optimal hospital conditions, where practices of basic hygiene and sanitation are often either luxuries or unknown to caretakers and where disposable needles and autoclavesare unavailable or too expensive. In modern hospitals with disposable needles and knowledge of basic hygiene and barrier nursing techniques,Ebolahas never spread on a large scale. In isolated settings such as a quarantined hospital or a remote village, most victims are infected shortly after the first case of infection is present. The quick onset of symptoms from the time the disease becomes contagious in an individual makes it easy to identify sick individuals and limits an individual's ability to spread the disease by traveling. Because bodies of the deceased are still infectious, some doctors had to take measures to properly dispose of dead bodies in a safe manner despite local traditional burial rituals. [ 27 ] Virology[ edit] Main article: Ebola virus GenusEbolavirus: species and their EVD-causing viruses Species name Virus name (abbreviation) Bundibugyo ebolavirus(accepted) [ 28 ] Bundibugyo virus(BDBV; previously BEBOV) Sudan ebolavirus Sudan virus(SUDV; previously SEBOV) Taï Forest ebolavirus Taï Forest virus(TAFV; previously CIEBOV) Zaire ebolavirus* Ebola virus(EBOV; previously ZEBOV) Table legend: *: The type species accepted: Taxon that has been accepted by the Executive Committee of the ICTV but that has yet to be ratified. Genome[