Part I History Transmission and Clinical Presentation US Department of Health and Human Services Centers for Disease Control and Prevention This presentation is current as of December ID: 914754
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Slide1
Ebola Virus Disease and Clinical Care:
Part I: History, Transmission, and Clinical Presentation
U.S. Department of Health and Human Services
Centers for Disease Control and Prevention
This presentation is current as of December 2014. This presentation contains materials from Centers for Disease Control and Prevention (CDC), Médecins Sans Frontières (MSF), and World Health Organization (WHO).
version 12.03.2014
Preparing Healthcare Workers to
Work in
Ebola Treatment Units (
ETUs)
in Africa
Slide2Learning Objectives
Describe the routes of Ebola virus transmissionExplain when and how patients are infectiousDescribe the clinical features of patients with Ebola Describe screening criteria for Ebola virus disease (EVD) used in West Africa
Explain how to identify patients with suspected EVD who present to the ETU
Slide3Viral Hemorrhagic Fevers
Arenaviridae
Bunyaviridae
Filoviridae
FlaviviridaeLassa HFArgentine HFBolivian HF
Venezuelan HFBrazilian HF
Hantavirus Genus
Congo-Crimean
HF
Rift
Valley FeverEbolaMarburgLloviuDengueYellow feverKyasanurOmsk
Slide4Ebola Virus
Slide5Ebola Transmission
This presentation contains materials from CDC, MSF, and WHO
Slide6Ebola Virus
Filoviridae Family of zoonotic RNA viruses: Marburg virus and
Ebola virus species
>20 previous Ebola
and
Marburg outbreaks
In previous outbreaks, the case-fatality rates have varied by subtype: E. Zaire (57%-90%), E. Sudan (approximately 50%), E. Bundibugyo (32%), and E. Reston (0%--evidence of infection but no clinical illness
).
Previous
West African case: Tai Forest Virus,
Côte d’Ivoire
Slide7Ebola Virus Transmission Cycle
Zoonotic virus– bats are the most likely reservoir, although species unknownSpillover event from infected animals to humans, followed by person-to-person transmission
Slide8Ebola Virus TransmissionSources
Transmission occurs via direct or indirect contact with body fluids from Ebola-infected
persons or animalsPotentially infectious body fluids include:
BloodRespiratory secretionsUrine Feces
VomitSalivaSweatBreast milk Semen, vaginal secretionsProlonged detection by PCR in semen (up to 101 days after infection and recovery)Transmission risk uncertain
Slide9Ebola Virus TransmissionKey Concepts
Infected persons are not contagious until onset of symptomsInfectiousness of body fluids (e.g., viral load) increases as patients become more
illCorpses are highly infectious Direct contact with an infected person or recently deceased person are the most common routes of transmission
Transmission also occurs through contact with objects or surfaces contaminated by blood or other body fluids containing virus
Slide10Ebola Virus Transmission
Routes of Virus EntryEstablished route – direct contact with blood or otherbody f
luidsEyes or other mucous membranesBreaks in the skin
Percutaneous injuries from objects contaminated with infectious materials (e.g., needlestick injury)Possible routesSexual contact
BreastfeedingAerosol transmission is unlikely Person-to-person transmission of Ebola virus via inhalation (aerosols) has not been demonstratedEpidemiology is not consistent with aerosol transmission
Slide11Ebola Virus Transmission
Opportunities for Person-to-Person TransmissionProviding routine care for infected personsHousehold or communityHealthcare
settingHandling or preparing corpses
Contact with objects contaminated by virus (e.g., soiled
linen, soiled clothes, or used utensils)Accidental injuries from virus-contaminated sharps
Slide12Ebola Virus TransmissionIncubation Period
The time from the moment of exposure to the virus until onset of symptoms or signs of diseaseIncubation period is usually 9-11 daysIncubation period ranges from 2 -21
days
Slide13Clinical Presentation
This presentation contains materials from CDC, MSF, and WHO
Slide14Initial Clinical Presentation of Ebola Virus Disease
Signs and symptomsFever, chills, myalgia, malaise, weakness, nausea, headacheGI symptoms very common: vomiting, diarrhea, abdominal painSpontaneous abortion/miscarriage
Hemorrhage is a late sign, occurring in <50% of cases, and much less common at presentationOther possible infectious causes of
signs and symptoms similar to EVDLassa fever, malaria, typhoid fever, meningococcemia, and other bacterial
infections – all very common in West AfricaDon’t expect all symptoms or consistent sequence in every patient
Slide15Clinical Features in Severe Ebola Virus Disease
Sepsis presentationHypovolemiaOliguria Signs of liver injuryCytokine storm Hemorrhagic symptoms (<50%)
Ranging from gum “oozing” to (less commonly) epistaxis or mucocutaneous bleeding, GI bleeding
Neuropsychiatric abnormalities (agitation, confusion)Acute malnutritionShock, multiple organ
failure
Slide16Initial Laboratory Findings of Ebola Virus Disease
Low platelet count (thrombocytopenia)Low WBC count (leukopenia)Electrolyte abnormalities from fluid shifts (e.g., diarrhea, fever, interstitial fluid leak)
Transaminitis (AST>ALT)Increased creatinineClotting abnormalities
Note: in many ETUs, few lab tests will be available
Slide17Clinical Appearance
Hematemesis
Slide18Clinical Appearance
Gingival Bleeding
Slide19Clinical Appearance
Bleeding from IV Site
Slide20Risk Factors for Death from Ebola Virus Disease
Patient characteristics Age <5 years or >45 years (perhaps related to viral load)Pregnancy
Exposure characteristicsLarge inoculum
Hollow bore needlestick
Exposure to corpse or patient with advanced diseaseClinical characteristics Short incubation time Rapid progression of symptoms Liver and kidney involvementUnexplained bleedingAltered mental status
Slide21Long-term Issues for Surviving Patients with Ebola
Arthralgia or myalgia (frequent, severe, and persistent)Cardiac injury (e.g. myocarditis)Cerebral complications (e.g., seizures, encephalopathy)Eye problemsMalnutritionMental health issues
Prolonged fatigue
Slide22Other Considerations for Patients with Fever or Hemorrhage
Many diseases in West Africa present with fever or have hemorrhagic manifestations
Amniotic fluid embolism
Gram-negative sepsis
Hemolytic-uremic syndrome
Lassa fever
Leptospirosis
Leukemia
Malaria
Meningitis
Plague
Rickettsial
diseases
Staphylococcal sepsis
Shigellosis
Thrombotic thrombocytopenic
purpura
Toxic shock syndrome
Typhoid fever
Viral hepatitis
Warfarin poisoning
It is important to consider and manage other treatable infections in the ETU.
Slide23Screening for Ebola
This presentation contains materials from CDC, MSF, and WHO
Slide24Case Definition for Screening Patients for Ebola
Applying a uniform case definition is critical for case identification, tracking, and control of the epidemicCase definitions for screening differ
by location (e.g., West Africa vs. United States)
Use the locally relevant case definition
Slide25Screening for ETU Referral
All patients must be screened (triaged) before entering the ETUNot done in high-risk PPE
Healthcare workers should perform triage at least one meter (three feet) from potential patientsPurpose of triage is to quickly isolate patients who might have EVD then obtain diagnostic tests
Most ETUs perform screening using case definition recommended by WHO for suspected
EVD in AfricaSlightly different case definitions could be used in different locationsIf screening assessment indicates patient is suspected of having Ebola, isolate immediately and admit to suspect area of ETU or arrange transfer to the ETU
Slide26Example: WHO Screening Algorithm for Healthcare Facilities in
Guinea
Slide27WHO Definition of “Contact”
Any person having been exposed to a suspect, probable, or confirmed case of Ebola in at least one of the following ways:Has slept in the same household with a caseHas had direct physical contact with the case (alive or dead) during the illness
Has had direct physical contact with the (dead) case at the funeralHas touched his/her blood or body fluids during the
illnessHas touched his/her clothes or linens
Has been breastfed by the patient (baby) Contact’s exposure must have taken place less than 21 days before their identification as a contacthttp://www.who.int/csr/resources/publications/ebola/ebola-case-definition-contact-en.pdf
Slide28Summary
Incubation period range is 2-21 days, but most commonly 9-11 days after contactNo transmission before symptom onsetTransmission by direct contact with ill people, body fluids, contaminated materials,
corpses, animalsNonspecific early symptoms progress to signs of sepsis: hypovolemic
shock, multi-organ failure, and sometimes hemorrhagic diseaseAppropriate triage of patients with signs and symptoms
that could be EVD is critical to reducing risk for healthcare workers, other patients and the community
Slide29U.S. Department of Health and Human Services
Centers for Disease Control and Preventionhttp://www.cdc.gov/vhf/ebola