Ebola Virus Disease (EVD)

Marburg and Ebola Virus Hemorrhagic Fevers• Filovirus

• RNA virus• Threadlike, filamentous

morphology• Viral epidemics from

Africa and a source in the Phillippines

• Humans, monkeys, chimpanzees and gorrillas are the major disease targets

Ebola Virus Disease (EVD)

▶ Formerly known as Ebola hemorrhagic fever

▶ Severe, often fatal in humans– Outbreaks have a case fatality rate < 90%

• Median 60%

– Outbreaks usually occur in remote villages of Central and West Africa

EVD Outbreaks

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Ebolavirus Outbreaks

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Ebolavirus

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Human Infection

Direct Contact•Blood•Secretions•Organs•Other body fluids

Indirect Contact•Contaminated environments

Airborne Transmission•Hypothetical during aerosol generating procedures

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EVD Transmission

1976 Zaire Ebola epidemic

• Driven by the use of improperly sterilized needles

and syringes, resulting in much of the geographic

spread of infection

• Person to person spread was extensive among

medical staff, often resulting in closure of hospitals

and clinics

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EVD Transmission

1976 Zaire Ebola epidemic

• Subsided with the use of properly sterilized

equipment, closure of hospitals, education of the

population, and institution of mask-gown-glove

precautions

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Dowell SF, Mukunu R, Ksiazek TG, et al.: Transmission of Ebola hemorrhagic fever: A study of risk factors in family members, Kikwit, Zaire 1995. J Infect Dis. 179 (Suppl 1):S87-S91 1999

World Health Organization: Ebola haemorrhagic fever in Zaire, 1976: Report of an international commission. Bull World Health Organ. 56:271-293 1978

Khan AS, Kweteminga TF, Heymann DH, et al.: The reemergence of Ebola hemorrhagic fever (EHF), Zaire, 1995. J Infect Dis. 179 (Suppl 1):S76-S86 1999

You Can’t Get Ebola From

EVDIncubation Period

• 2 – 21 days (mean 8 - 10 days)

Acute onset• Fever (> 38o6C/>101.5oF), myalgia, headache

After about five days• Nausea and vomiting• Abdominal pain• Diarrhea• Chest pain, cough, pharyngitis

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EVD• Other features

• Photophobia• Lymphadenopathy• Conjunctivitis• Jaundice• Pancreatitis• CNS Symptoms

• Decreased mental status, delirium, coma

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EVD• As disease progresses

• Erythematous maculopapular rash • face, neck, trunk, arms

• desquamation

• Bleeding manifestations• petechiae, ecchymosis

• hemorrhage less common

• Shock, DIC, liver and renal failure

• Death between six and 16 days

• Protracted convalescence• Arthralgia, orchitis, uveitis, transverse myelitis

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EVD

• Infectious as long as ebola virus present in blood and secretions• Can be up to 61 days in semen

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Diagnosis

• Travel + Exposure history

• Progressive abdominal pain + diarrhea• Rash

• Thrombocytopenia, leukopenia, lymphompenia• Elevated transaminases: AST > ALT• Elevated amylase, D-dimer, low albumin• Prolonged PT, PTT

• Viral culture during acute stages• Seroconversion during second week of illness

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CDC Case Definition – Suspect Case

1. Clinical Criteria• Fever > 38.6oC or >101.5oF • Symptoms such as severe headache, muscle pain, vomiting, diarrhea,

abdominal pain, or unexplained hemorrhage

AND

2. Epidemiologic risk factors within the past 21 days before the onset of symptoms• Contact with blood or other body fluids or human remains of a patient known to

have or suspected to have EVD• Residence in—or travel to—an area where EVD transmission is active• Direct handling of bats, rodents, or primates from disease-endemic areas

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CDC Case Definition - Contacts1. High Risk Exposure• Percutaneous or mucous membrane exposure to body fluids of EVD patient• Direct care or exposure to body fluids of an EVD patient without appropriate

PPE• Laboratory worker processing body fluids of confirmed EVD patients without

appropriate PPE or standard biosafety precautions• Participation in funeral rites which include direct exposure to human remains

in the geographic area where outbreak is occurring without appropriate PPE

2. Low Risk Exposure• Household member or other casual contact with an EVD patient• Providing patient care or casual contact without high-risk exposure with EVD

patients in health care facilities in EVD outbreak affected countries

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EVD Treatment• Supportive• Maintenance of hydration• Replacement of coagulation factors and

platelets as indicated• Treatment of DIC

• Monkey models• activated protein C improved survival• recombinant inhibitor of the tissue factor–activated

factor VII complex improved survival

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Hensley LE, Stevens EL, Yan SB, et al.: Recombinant human activated protein C for the postexposure treatment of Ebola hemorrhagic fever. J Infect Dis. 196 (Suppl 2)):S390-S399 2007Geisbert TW, Hensley LE, Jahrling PB, et al.: Treatment of Ebola virus infection with a recombinant inhibitor of factor VIIa/tissue factor: A study in rhesus monkeys. Lancet. 362:1953-1958 2003

Infection Prevention• Contact + Droplet Isolation (with a twist)

• Surgical mask (N95 respirator if aerosol generating procedure)

• Eye protection with goggles/face shield

• Fluid resistant gowns

• 12” Gloves (double glove)

• Leg and foot protection if diarrhea, vomiting, hemmorhage

• Cleaning with bleach

• Exposure• Wash, wash and wash again

• Twice daily fever check-up for 21 days

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Putting On and Taking Off

Putting On1.Gown2.Mask or N95 Respirator3.Face Shield4.Gloves

Removing1.Gloves2.Face Shield3.Gown4.Mask or N95 Respirator

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