Ebola Virus Disease

Course #94082 - $20 • 4 Hours/Credits


Self-Assessment Questions

    1 . The Ebola virus was first described in
    A) 1842.
    B) 1921.
    C) 1976.
    D) 1998.

    THE EBOLA VIRUS

    Ebola virus was discovered in 1976, when it was identified as the cause of an outbreak of hemorrhagic fever near the Ebola river in Democratic Republic of Congo (formerly Zaire). Sporadic cases and small outbreaks of EVD were reported subsequently in sparsely populated regions of Central Africa. The 2014–2016 outbreak began in the West Africa country of Guinea and spread rapidly to the neighboring countries of Sierra Leone and Liberia [3,7].

    Click to Review



    2 . Which of the following species of Ebola virus is found in the Philippines and China?
    A) Zaire ebolavirus.
    B) Reston ebolavirus.
    C) Taï Forest ebolavirus.
    D) Bundibugya ebolavirus.

    THE EBOLA VIRUS

    EBOLA VIRUSES

    SpeciesVirusEndemic Countries
    Bundibugyo ebolavirus Bundibugyo virus (BDBV)Uganda
    Zaire ebolavirus Ebola virus (EBOV)Democratic Republic of Congo
    Reston ebolavirus Reston virus (RESTV)Philippines, China
    Sudan ebolavirus Sudan virus (SUDV)South Sudan
    Taï Forest ebolavirus Taï Forest virus (TAFV)Ivory Coast
    Click to Review



    3 . The 2014–2016 West Africa Ebola virus disease (EVD) outbreak has been linked to a possible reservoir in
    A) fruit bats.
    B) mangabeys.
    C) chimpanzees.
    D) African grey parrots.

    TRANSMISSION

    The natural reservoir of Ebola virus and the ecologic perturbations by which the virus emerges to infect humans are poorly understood [34]. EVD is considered a true zoonosis in that a reservoir of Ebola virus exists in the wild, combined with low-level infection in small mammals and nonhuman primates. Humans are an accidental host, increasingly so because of deforestation, hunting, and dietary practices that lead to increased contact with small animals. The 2014–2016 West Africa outbreak has been linked to consumption of fruit bats, which are sometimes used for dietary purposes [7]. Although filoviruses have been identified in bats, and EVD outbreaks have been temporally associated with bat migrations and die-offs, neither bats nor any other mammal has yet been accepted as a definitive Ebola virus reservoir [34].

    Click to Review



    4 . Ebola virus is thought to gain entry to the human host through
    A) the fecal-oral route.
    B) mucous membranes.
    C) abrasions in the skin.
    D) Both B and C

    EBOLA VIRUS DISEASE

    Ebola virus is thought to gain entry to the human host through mucous membranes or skin abrasions, after which it binds to receptors on the surface of macrophages, monocytes, and dendritic cells [2]. Infected macrophages and monocytes migrate to regional lymph nodes, where continued viral replication and cellular propagation of infection occurs. From lymph nodes, infected monocytes, macrophages, and free virions spread through the lymphatic system to the blood stream, liver, spleen, and adrenal glands. Amplification of infection at these distant sites leads to focal areas of tissue necrosis and the release of ever-increasing numbers of virions into the general circulation [2]. The trophism of Ebola virus extends to multiple cell types, including endothelial cells, fibroblasts, hepatocytes, and adrenocortical cells.

    Click to Review



    5 . The usual onset of symptoms of EVD is
    A) 2 to 3 days.
    B) 5 to 7 days.
    C) 8 to 10 days.
    D) 14 to 21 days.

    EBOLA VIRUS DISEASE

    As noted, EVD is an acute, severe, multisystem viral infection that is highly contagious and often fatal [1,3,8,9,33]. The onset of symptoms is usually 5 to 7 days after exposure, though the observed incubation period varies from 2 to 21 days. Illness begins abruptly with fever, chills, and malaise, followed soon after by the rapid onset of weakness, myalgia, headache, vomiting, diarrhea, and abdominal pain. An erythematous maculopapular rash, appearing first on the buttocks and trunk, then more generalized, is often seen between the 5th and 7th day of illness [8]. Other findings include pharyngitis, lymph node enlargement, hepatomegaly, and abdominal tenderness.

    Click to Review



    6 . In residents of or travelers from Central Africa, differential diagnosis in persons with suspected EVD should include all of the following, EXCEPT:
    A) Malaria
    B) Dengue fever
    C) Meningococcal septicemia
    D) Severe acute respiratory syndrome (SARS)

    EBOLA VIRUS DISEASE

    The presentation of a febrile patient in an endemic area or after foreign travel raises suspicion for a variety of common acute infections, depending on geographic locale. In residents of or travelers from Central Africa, primary considerations are malaria, typhoid, shigellosis, leptospirosis, dengue fever, rickettsiosis, meningoccocal septicemia, relapsing fever, and hepatitis [1,10].

    Click to Review



    7 . Which of the following laboratory tests for EVD is appropriate later in the disease course or after recovery?
    A) Virus isolation
    B) IgM and IgG antibodies
    C) Polymerase chain reaction (PCR)
    D) Enzyme-linked immunosorbent assay (ELISA)

    EBOLA VIRUS DISEASE

    LABORATORY TESTS USED IN DIAGNOSIS OF EVD

    Timeline of InfectionDiagnostic Tests Available
    Within a few days after symptoms begin
    Antigen-capture enzyme-linked immunosorbent assay (ELISA) testing
    IgM ELISA
    Polymerase chain reaction (PCR)
    Virus isolation
    Later in disease course or after recoveryIgM and IgG antibodies
    Retrospectively in deceased patients
    Immunohistochemistry testing
    PCR
    Virus isolation
    Click to Review



    8 . What antiviral medication is approved in the United States for the treatment of EVD?
    A) ZMapp
    B) Favipiravir
    C) Fomivirsen
    D) No antiviral medications are approved for this use.

    EBOLA VIRUS DISEASE

    There is no satisfactory antiviral agent for treatment of EVD. Care is supportive and initial management goals include fluid resuscitation, prevention of intravascular volume depletion, and correction of electrolyte and other metabolic abnormalities [9,11]. Severe hypokalemia and varying degrees of lactic acidosis are common. Vigilance is required in order to keep up with fluid losses from vomiting and diarrhea and prevent complications of shock (e.g., metabolic acidosis, acute renal failure, acute lung injury).

    Click to Review



    9 . The 2014–2016 Ebola virus outbreak has been traced to an index case in
    A) Liberia.
    B) Nigeria.
    C) Guinea.
    D) Sierra Leone.

    THE 2014–2016 EBOLA EPIDEMIC IN WEST AFRICA

    The 2014–2016 outbreak has been traced to an index case in Guinea involving a child hospitalized in December 2013. In March 2014, public health officials in Guinea reported more than 40 additional cases, the first formal indication of a regional outbreak [7]. It is thought that during the initial stages of the outbreak severely ill patients were taken to provincial hospitals, where unsuspecting staff and visitors came into direct contact with patients. This in turn led to secondary foci of infection, further expanding the outbreak and establishing new chains of transmission.

    Click to Review



    10 . The majority of cases in the 2014–2016 Ebola virus outbreak in West Africa occurred in persons
    A) 0 to 3 years of age.
    B) 10 to 24 years of age.
    C) 15 to 44 years of age.
    D) older than 50 years of age.

    THE 2014–2016 EBOLA EPIDEMIC IN WEST AFRICA

    Contiguous regions in Liberia, Sierra Leone, and Guinea in West Africa constitute the major locus of the epidemic. A small number of cases appeared transiently in Nigeria, where control measures appear to have been effective in limiting spread. In an analysis of 4,507 cases reported for the first nine months of the outbreak, the World Health Organization (WHO) found that the majority of cases occurred in persons 15 to 44 years of age, and the mean incubation period was 11 days, with a range of 2 to 21 days [3]. Lower attack rates in young children and older adults and higher rates in women presumably reflects differences in exposures associated with caregiving for ill persons [34]. The estimated case fatality rate for the period reported was 71% overall, 64% among hospitalized patients, and 56% among healthcare workers.

    Click to Review



    11 . During the 2014–2016 outbreak, active screening to prevent persons with EVD from boarding planes included screening all outbound passengers in epidemic areas using
    A) a health questionnaire.
    B) temperature monitoring.
    C) assessment of symptoms.
    D) All of the above

    THE 2014–2016 EBOLA EPIDEMIC IN WEST AFRICA

    During the course of the West Africa outbreak, the CDC provided personnel to assist with active screening and education efforts on the ground in West Africa, aimed at preventing sick travelers from boarding a plane. In addition, airports in Liberia, Sierra Leone, and Guinea screened all outbound passengers by means of a health questionnaire, symptom assessment, and temperature monitoring.

    Click to Review



    12 . Active post-arrival monitoring of travelers entering the United States from countries experiencing an Ebola outbreak continues for
    A) 7 days.
    B) 21 days.
    C) 30 days.
    D) 60 days.

    THE 2014–2016 EBOLA EPIDEMIC IN WEST AFRICA

    Active post-arrival surveillance included travelers without fever or other symptoms consistent with Ebola, who were monitored daily by state and local health departments for 21 days from the date of their departure from West Africa. Six states (New York, Pennsylvania, Maryland, Virginia, New Jersey, and Georgia), accounting for the large majority of such travelers, implemented active post-arrival monitoring in late October 2014. The CDC also provided post-arrival surveillance assistance to state and local health departments, including information on travelers arriving in their states, and upon request, technical support, consultation, and funding.

    Click to Review



    13 . All persons entering the room of a patient with known or suspected EVD should wear at least
    A) gloves.
    B) gloves and a gown.
    C) gloves, a gown, eye protection, and a facemask.
    D) gloves, a gown, eye protection, and a respirator.

    CLINICAL CASE MANAGEMENT: ADVANCED PLANNING

    All persons entering the patient room should wear at least:

    • Gloves

    • Gown (fluid resistant or impermeable)

    • Eye protection (goggles or face shield)

    • Facemask

    Click to Review



    14 . Providing care to patients with EVD during aerosol-generating procedures requires additional protections. Which of the following is considered to be aerosol-generating?
    A) Suturing
    B) Nebulization
    C) Environmental cleaning
    D) Intubation and extubation

    CLINICAL CASE MANAGEMENT: ADVANCED PLANNING

    Trained personnel, using PPE as described for routine patient care, should be in charge of collection and handling of soiled re-usable respirators. Although there are limited data available to definitively define AGPs, procedures that are usually included are bilevel positive airway pressure (BiPAP), bronchoscopy, sputum induction, intubation and extubation, and open suctioning of airways.

    Click to Review



    15 . Healthcare personnel who develop possible signs of EVD after an unprotected exposure to a patient with EVD should
    A) notify a supervisor.
    B) report to work immediately.
    C) halt work for five to seven days.
    D) delay notification of local and state health departments until diagnosis is confirmed.

    CLINICAL CASE MANAGEMENT: ADVANCED PLANNING

    Healthcare personnel who develop sudden-onset fever, intense weakness or muscle pains, vomiting, diarrhea, or any signs of hemorrhage after an unprotected exposure (e.g., not wearing recommended PPE at the time of patient contact) to a patient with EVD should:

    • Not report to work or should immediately stop working

    • Notify their supervisor

    • Seek prompt medical evaluation and testing

    • Notify local and state health departments

    • Comply with work exclusion until they are deemed no longer infectious to others

    Click to Review



    16 . All of the following are considered high-risk exposures to Ebola virus, EXCEPT:
    A) Persons who spent time in a healthcare facility where EVD patients are being treated
    B) Laboratory processing of body fluids of suspected or confirmed EVD cases without appropriate protective equipment or standard biosafety precautions
    C) Participation in funeral rites or other direct exposure to human remains in the geographic area where the outbreak is occurring without appropriate protective equipment
    D) Percutaneous or mucous membrane exposure or direct skin contact with body fluids of a person with a confirmed or suspected case of EVD without appropriate protective equipment

    EXPOSURE EVALUATION PROTOCOL

    The known or estimated level of risk exposure should guide testing of persons for possible Ebola virus infection. The CDC recommends testing for all persons with onset of fever within 21 days of having a high-risk exposure. A high-risk exposure includes any of the following:

    • Percutaneous or mucous membrane exposure or direct skin contact with body fluids of a person with a confirmed or suspected case of EVD without appropriate PPE

    • Laboratory processing of body fluids of suspected or confirmed EVD cases without appropriate PPE or standard biosafety precautions

    • Participation in funeral rites or other direct exposure to human remains in the geographic area where the outbreak is occurring without appropriate PPE

    Click to Review



    17 . What is the minimum sample of serum, plasma, or whole blood that should be collected when testing for possible EVD?
    A) 0.1 mL
    B) 1 mL
    C) 4 mL
    D) 10 mL

    DIAGNOSTIC SPECIMEN COLLECTION AND HANDLING

    For adults, a minimum volume of 4 mL whole blood is preferable. For pediatric samples, a minimum of 1 mL whole blood should be collected in pediatric-sized collection tubes. Blood must be collected in plastic collection tubes. Do not transport or ship specimens in glass containers or in heparinized tubes.

    Click to Review



    18 . Specimens submitted to the CDC for EVD testing should be
    A) in glass containers.
    B) packaged and transported at 2° to 8° C.
    C) preserved in heparin tubes.
    D) submitted without consultation with the CDC.

    DIAGNOSTIC SPECIMEN COLLECTION AND HANDLING

    Specimens should be packaged and transported at 2°–8°C with cold-packs to the final testing destination. Specimens other than blood may be submitted after consultation with CDC by calling the Emergency Operations Center at 770-488-7100.

    Click to Review



    19 . Which of the following statements regarding the handling of human remains if a patient with EVD dies is TRUE?
    A) Cremation is prohibited.
    B) Remains may be buried in a sealed casket.
    C) The remains should be embalmed as soon as possible.
    D) Autopsies may be conducted without the need for additional precautions.

    HANDLING OF HUMAN REMAINS

    If the patient dies, handling of the body should be minimized, and the remains should not be embalmed. Instead, remains should be wrapped in sealed, leak-proof material and cremated or buried promptly in a sealed casket. If an autopsy is necessary, the state health department and the CDC should be consulted regarding appropriate precautions.

    Click to Review



    20 . Visitors of persons with EVD in a healthcare facility should be
    A) evaluated for their ability to comply with precautions.
    B) screened for active Ebola infection before entering or upon arrival to the hospital.
    C) provided with instruction on hand hygiene, limiting surfaces touched, and use of protective equipment.
    D) All of the above

    MONITORING, MANAGEMENT, AND TRAINING OF VISITORS

    Visits should be scheduled and controlled to allow for:

    • Screening for active Ebola infection (e.g., fever and other symptoms) before entering or upon arrival to the hospital

    • Evaluating risk to the health of the visitor and ability to comply with precautions

    • Providing instruction before entry into the patient care area on hand hygiene, limiting surfaces touched, and use of PPE according to the current facility policy while in the patient's room

    Click to Review