II. Epidemiology

  1. Marburg Virus
    1. Outbreaks in Europe 1967, Congo 2000, Angola 2005
  2. Ebola Virus
    1. Five species with varying regions affected and mortality rates
    2. Outbreaks in Zaire 1976, Sudan 1970, Philipines 1989, Zaire 1995, Uganda 2000, Sudan 2004, Uganda 2007
    3. Ebola epidemic in West Africa (2014) in Sierra Leone, Guinea and Liberia
      1. By far, the largest Ebola or Marburg outbreak
      2. As of November 2014, West Africa: 13000 cases (nearly 8000 lab confirmed) and 4800 deaths
      3. A few cases have presented in Mali, Senegal, Nigeria, Spain and the U.S.

III. Pathophysiology

  1. Ebola Virus (Filovirus family)
    1. Nonsegmented, negative-sense, single-stranded RNA Virus
    2. Structurally similar to Rhabdovirus (Rabies) and Paramyxovirus (Measles)
  2. Hemorrhagic Fever viruses (associated coagulation deficits, DIC)
    1. Other hemorrhagic fever viruses include Lassa Fever, Yellow Fever, Dengue Fever
  3. Host organism
    1. Small animal host is suspected (e.g. bats)
    2. Primates appear to be as susceptible as humans to high mortality rates
      1. Exposure to infected primates has been responsible for many of the initial source cases in epidemics
  4. Spread by close contact
    1. Infected blood
    2. Body fluid (especially blood, stool and vomit)
    3. Body tissue
    4. Air borne transmission is unlikely (unless aerosolized, typically during medical procedures)

IV. Course

  1. Incubation period: 8-12 days (ranges from 2 to 21 days)
  2. Mortality is highest days 6 to 16
  3. Surviving patients start to improve by the second week of illness
  4. Virus may persist in semen and Breast Milk for a prolonged period beyond recovery
  5. Prolonged recovery characterized by weakness, Fatigue and persistent weight loss

V. Symptoms: Common

  1. Fever (87%)
  2. Fatigue (76%)
  3. Vomiting (68%)
  4. Diarrhea (66%)
  5. Anorexia (65%)

VI. Findings: Manifestations

  1. Influenza-Like Illness
    1. Abrupt onset fever, chills and malaise
    2. Weakness and Anorexia
    3. Severe Headache
    4. Trunk and back pain
    5. Nonproductive cough and Sore Throat
    6. May rapidly progress to Septic Shock and multi-organ failure
  2. Dermatitis
    1. Variably present by day 5-7 of illness
    2. Non-pruritic diffuse erythematous rash that may spare the legs (with or without Desquamation)
  3. Gastrointestinal symptoms
    1. Onset within a few days of initial symptoms
    2. Diarrhea, Vomiting and severe Abdominal Pain
    3. Bloody stools may occur (6% of cases)
  4. Bleeding
    1. Variably present in 20% of cases and a late manifestation
    2. Signs include Petechiae or Ecchymosis, mucosal bleeding or gastrointestinal Hemorrhage
  5. Neurologic
    1. Seizures, confusion and cerebral edema may occur
  6. Cardiopulonary
    1. Chest Pain, Shortness of Breath, Hiccups may occur
  7. Other findings
    1. Dark-red palatal discoloration
    2. Conjunctival injection

VII. Labs

  1. Precautions
    1. CDC recommends that labs be performed on dedicated machine (e.g. iStat) not used for other patient's blood
    2. Logistically, labs are typically being deferred to tertiary center or department of health testing in high suspicion cases
  2. Complete Blood Count (CBC) with differential and Platelet Count
    1. Leukopenia
    2. Thrombocytopenia
  3. Coagulation tests
    1. Findings consistent with Disseminated Intravascular Coagulation (DIC)
    2. Prothrombin (PT/INR) prolonged
    3. Partial Thromboplastin Time (PTT) prolonged
  4. Liver Function Tests
    1. Serum Aspartate Aminotransferase (AST) increased (more than ALT)
    2. Alanine Aminotransferase (ALT) increased

VIII. Prognosis

  1. Mortality rates range from 50-90%
  2. West African Ebola epidemic in 2014 mortality: 70%
  3. Findings suggestive or worse prognosis
    1. Tachypnea
    2. Anuria
    3. Delirium to coma
    4. Refractory shock
    5. Persistently high or increasing Ebola Virus RNA titers

IX. Prevention

  1. Full Personal Protective Equipment (PPE) for healthcare workers (donning and doffing)
    1. http://www.cdc.gov/HAI/pdfs/ppe/ppeposter148.pdf

XI. References

  1. Bray in Hirsch (2014) Ebola and Marburg Virus Disease, UpToDate, accessed online 11/5/2014
  2. (1995) MMWR Morb Mortal Wkly Rep 44:381-2 [PubMed]

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Ontology: Ebolavirus (C0949892)

Definition (NCI_CDISC) Any viral organism that can be assigned to the genus Ebola virus.
Definition (NCI) A genus of filamentous, enveloped viruses with glycoprotein surface spikes, in the family Filoviridae. The genome is composed of a linear single-strand of negative sense RNA. The primary product of gene transcription of the fourth gene is a small glycoprotein (sGP), while RNA editing allows expression of full length glycoprotein. The Ebolavirus natural reservoir is considered to be fruit bats of the Pteropodidae family and cause severe hemorrhagic fevers in humans.
Definition (MSH) A genus in the family FILOVIRIDAE consisting of several distinct species of Ebolavirus, each containing separate strains. These viruses cause outbreaks of a contagious, hemorrhagic disease (HEMORRHAGIC FEVER, EBOLA) in humans, usually with high mortality.
Concepts Virus (T005)
MSH D029043
SnomedCT 424206003, 407342005
English Ebola Virus, Ebola Viruses, Virus, Ebola, Viruses, Ebola, Ebola-like Viruses, Ebolaviruses, Ebola-like viruses, Genus Ebolavirus (organism), Genus Ebolavirus, Ebola virus, Ebolavirus, Ebola like Viruses, Ebola-like Virus, Genus Ebola-like viruses (organism), Genus Ebola-like viruses, Ebola-like virus, EBOV, EBOLA VIRUS
Portuguese Ebolavirus, Vírus Ebola-Like, Vírus Similares ao Ebola, Vírus Semelhantes ao Vírus Ebola, Vírus Similares ao Vírus Ebola
Italian Virus Ebola, Ebolavirus, Virus tipo Ebola
French Ebolavirus, Ebola virus, Virus Ebola, Virus de type Ebola
Swedish Ebolavirus
Spanish género Ebolavirus, género Ebolavirus (organismo), Ebolavirus, virus Ébola, género de virus tipo Ébola (organismo), género de virus tipo Ébola
Finnish Ebola-virus
Czech Ebolavirus, viry podobné viru Ebola
Japanese エボラウイルス-ザイール, レストンエボラウイルス, エボタウイルス-コートジボアール, エボラウイルス-レストン, コートジボアールウイルス, コートジボアール-エボラウイルス, スーダンエボラウイルス, 象牙海岸ウイルス, レストンウイルス, ザイールウイルス, ザイールエボラウイルス, スーダンウイルス, エボラウイルス-スーダン, エボラウイルス, エボラ様ウイルス
Polish Wirus Ebola, Wirusy grupy Ebola, Wirusy Ebola-podobne
German Ebola-artige Viren