Ebola virus disease

Ebola virus disease
SynonymsEbola hemorrhagic fever (EHF), Ebola
7042 lores-Ebola-Zaire-CDC Photo.jpg
Two nurses standing near Mayinga N'Seka, a nurse with Ebola virus disease in the 1976 outbreak in Zaire. N'Seka died a few days later.
SpecialtyInfectious disease
SymptomsFever, sore throat, muscular pain, headaches, diarrhea, bleeding[1]
ComplicationsLow blood pressure from fluid loss[2]
Usual onset2 days to 3 weeks post exposure[1]
CausesEbolaviruses spread by direct contact[1]
Diagnostic methodFinding the virus, viral RNA, or antibodies in blood[1]
Differential diagnosisMalaria, cholera, typhoid fever, meningitis, other viral hemorrhagic fevers[1]
PreventionCoordinated medical services, careful handling of bushmeat[1]
TreatmentSupportive care[1]
Prognosis25–90% mortality[1]

Ebola virus disease (EVD), also known as Ebola hemorrhagic fever (EHF) or simply Ebola, is a viral hemorrhagic fever of humans and other primates caused by ebolaviruses.[1] Signs and symptoms typically start between two days and three weeks after contracting the virus with a fever, sore throat, muscular pain, and headaches.[1] Vomiting, diarrhea and rash usually follow, along with decreased function of the liver and kidneys.[1] At this time, some people begin to bleed both internally and externally.[1] The disease has a high risk of death, killing between 25 and 90 percent of those infected, with an average of about 50 percent.[1] This is often due to low blood pressure from fluid loss, and typically follows six to sixteen days after symptoms appear.[2]

The virus spreads through direct contact with body fluids, such as blood from infected humans or other animals.[1] Spread may also occur from contact with items recently contaminated with bodily fluids.[1] Spread of the disease through the air between primates, including humans, has not been documented in either laboratory or natural conditions.[3] Semen or breast milk of a person after recovery from EVD may carry the virus for several weeks to months.[1][4][5] Fruit bats are believed to be the normal carrier in nature, able to spread the virus without being affected by it.[1] Other diseases such as malaria, cholera, typhoid fever, meningitis and other viral hemorrhagic fevers may resemble EVD.[1] Blood samples are tested for viral RNA, viral antibodies or for the virus itself to confirm the diagnosis.[1]

Control of outbreaks requires coordinated medical services and community engagement.[1] This includes rapid detection, contact tracing of those who have been exposed, quick access to laboratory services, care for those infected, and proper disposal of the dead through cremation or burial.[1][6] Samples of body fluids and tissues from people with the disease should be handled with special caution.[1] Prevention includes limiting the spread of disease from infected animals to humans by handling potentially infected bushmeat only while wearing protective clothing, and by thoroughly cooking bushmeat before eating it.[1] It also includes wearing proper protective clothing and washing hands when around a person with the disease.[1] No specific treatment or vaccine for the virus is available, although a number of potential treatments are being studied.[1] Supportive efforts, however, improve outcomes.[1] This includes either oral rehydration therapy (drinking slightly sweetened and salty water) or giving intravenous fluids as well as treating symptoms.[1]

The disease was first identified in 1976 in two simultaneous outbreaks: one in Nzara (a town in South Sudan) and the other in Yambuku (Democratic Republic of the Congo), a village near the Ebola River from which the disease takes its name.[7] EVD outbreaks occur intermittently in tropical regions of sub-Saharan Africa.[1] Between 1976 and 2013, the World Health Organization reports a total of 24 outbreaks involving 1,716 cases.[1][8] The largest outbreak to date was the epidemic in West Africa, which occurred from December 2013 to January 2016 with 28,616 cases and 11,310 deaths.[9][10][11] It was declared no longer an emergency on 29 March 2016.[12] Other outbreaks in Africa began in the Democratic Republic of the Congo in May 2017,[13][14] and 2018.[15][16]

Signs and symptoms

Signs and symptoms of Ebola[17]

Onset

The length of time between exposure to the virus and the development of symptoms (incubation period) is between 2 and 21 days,[1][17] and usually between 4 and 10 days.[18] However, recent estimates based on mathematical models predict that around 5% of cases may take greater than 21 days to develop.[19]

Symptoms usually begin with a sudden influenza-like stage characterized by feeling tired, fever, weakness, decreased appetite, muscular pain, joint pain, headache, and sore throat.[1][18][20][21] The fever is usually higher than 38.3 °C (101 °F).[22] This is often followed by nausea, vomiting, diarrhea, abdominal pain, and sometimes hiccups.[21][23] The combination of severe vomiting and diarrhea often leads to severe dehydration.[24] Next, shortness of breath and chest pain may occur, along with swelling, headaches, and confusion.[21] In about half of the cases, the skin may develop a maculopapular rash, a flat red area covered with small bumps, five to seven days after symptoms begin.[18][22]

Bleeding

In some cases, internal and external bleeding may occur.[1] This typically begins five to seven days after the first symptoms.[25] All infected people show some decreased blood clotting.[22] Bleeding from mucous membranes or from sites of needle punctures has been reported in 40–50% of cases.[26] This may cause vomiting blood, coughing up of blood, or blood in stool.[27] Bleeding into the skin may create petechiae, purpura, ecchymoses or hematomas (especially around needle injection sites).[28] Bleeding into the whites of the eyes may also occur.[29] Heavy bleeding is uncommon; if it occurs, it is usually in the gastrointestinal tract.[30] The incidence of bleeding into the gastrointestinal tract has decreased since earlier epidemics and is now estimated to be approximately 10% with improved prevention of disseminated intravascular coagulation.[24]

Recovery and death

Recovery may begin between 7 and 14 days after first symptoms.[21] Death, if it occurs, follows typically 6 to 16 days from first symptoms and is often due to low blood pressure from fluid loss.[2] In general, bleeding often indicates a worse outcome, and blood loss may result in death.[20] People are often in a coma near the end of life.[21]

Those who survive often have ongoing muscular and joint pain, liver inflammation, decreased hearing, and may have continued tiredness, continued weakness, decreased appetite, and difficulty returning to pre-illness weight.[21][31] Problems with vision may develop.[32]

Survivors develop antibodies against Ebola that last at least 10 years, but it is unclear whether they are immune to additional infections.[33]

Other Languages
Afrikaans: Ebola
Alemannisch: Ebolafieber
አማርኛ: ኢቦላ
bamanankan: Ebola virisi bana
български: Ебола
bosanski: Ebola (bolest)
čeština: Ebola
Chi-Chewa: Matenda a Ebola
dansk: Ebola
Deutsch: Ebolafieber
Esperanto: Ebola malsano
eʋegbe: Ebola dɔlele
føroyskt: Ebola
Fulfulde: Ebola
galego: Ébola
hrvatski: Ebola
Bahasa Indonesia: Penyakit virus Ebola
עברית: אבולה
Basa Jawa: Panyakit ebola
қазақша: Эбола ауруы
Kinyarwanda: Indwara ya Ebola
Kiswahili: Ebola
Kreyòl ayisyen: Maladi viris Ebola
Limburgs: Ebola
lingála: Bokono ya Ebola
मैथिली: इबोला
македонски: Ебола
മലയാളം: എബോള
Bahasa Melayu: Penyakit virus Ebola
монгол: Эбола
Nederlands: Ebola
Nedersaksies: Ebola
नेपाली: इबोला
norsk nynorsk: Ebola-virussjukdom
occitan: Virus Ebola
oʻzbekcha/ўзбекча: Ebola gemorragik isitmasi
Papiamentu: Ebola
ភាសាខ្មែរ: ជំងឺអ៊ីបូឡា
Romani: Ebola
Simple English: Ebola virus disease
slovenščina: Ebola
српски / srpski: Ебола
srpskohrvatski / српскохрватски: Ebola
suomi: Ebola
svenska: Ebolafeber
татарча/tatarça: Эбола бизгәге
Thuɔŋjäŋ: Ebuɔla
Tiếng Việt: Bệnh do virus Ebola
walon: Five Ebola
žemaitėška: Ebuola
Kabɩyɛ: Eeboolaa