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THE EBOLA VIRUS EPIDEMIC Current Status and Future Prospects
William Schaffner, MDProfessor of Preventive Medicine and Infectious Diseases
Vanderbilt University Medical Center
Consultant, Communicable Disease ControlTennessee Department of Health
OUTLINE
Ebolavirus ecology and epidemiology
Ebolavirus disease – clinical aspects
Public Health Response
Research: Treatment and Vaccines
Ebola in the USA
Filovirus family (filo, Latin for filament)Hemorrhagic Fever Viruses
Five subtypes
West African epidemic: Zaire subtype
Ebolavirus Ecology
• Likely reservoir: Fruit bats– Large, roost in large colonies, migrate
• Infected hosts: Great apes, forest antelopes
Humans likely infected via hunting/butchering animals
Perhaps contact with bat urine, droppings or saliva on partially eaten fruit
EBOLA CLINICAL ASPECTS - 1
Incubation period 5-10 Days (range, 2-19)
ONSET: Abrupt – Fever, Headache, Myalgia
Soon Thereafter: Nausea, Vomiting, Abdominal Pain, Diarrhea
Ongoing: Jaundice, Pancreatitis CNS – Somnolence, Delirium, Coma
Bleeding (1/3) – Petechiae, Hemorrhages
EBOLA CLINICAL ASPECTS - 2
Electrolyte abnormalities – sodium and potassium loss
Liver failure → low serum protein → edema
Bleeding from low platelets
Fatality rate, current outbreak: ~50%
Human – to – Human Transmission
Patients become infectious to others when they become sick
Ebolavirus is NOT spread by respiratory route
Spread from intimate contact with body fluids or tissues of a sick person or a corpse
Two Primary Risk Groups for Transmission
• Healthcare workers: all who touch patients, soiled environment, funeral/burial workers
• Family members– Caring for the sick– Preparation of loved one’s body for burial cultural bathing, touching of respect
2 y.o. boyGueckedou, Guinea
Intersection of 3 nations
Dec, 2013
1 weekMother, sister, grandmother
Mourners to another villageHealth workeranother village
doctorRelatives other towns
Relatives other towns
Ebola recognizedDozens Dead in 8 Guinean towns
Suspected cases in Liberia, Sierra Leone
Funeral of traditional healer14 women infected
Koindu, Sierra Leone
Mar, 2014
MOLECULAR GENETIC STUDY OF THE WEST AFRICAN EBOLA VIRUS
Investigators: Harvard, Broad Institute, Kenema Hospital in Sierra Leone
Sequenced RNA, 99 virus samples
All the viruses are closely related-traced back to single introduction by traditional healer
Outbreak NOT caused by repeated introductions from nature: all human-to-human spread
Contributions to Rapid Spread - 1
• Previous outbreaks in small, remote villages• Current: A border region, more dense population
Roads improved, people travel a lot• West Africa had not experienced Ebola before• Economy poor, low education, recent political
instability• Rumors that Ebola was a myth or a political fiction
Contributions to Rapid Spread - 2
• Limited healthcare facilities, few healthcare personnel poorly trained, no personal protective supplies
• Abandonment of healthcare facilities• Facilities refuse to treat anyone with
suggestive symptoms• Families keep ill at home and keep quiet to
avoid stigma
HEALTHCARE LIMITATIONS
“Beds” may be pallets on the floor or ground
Facilities often do not provide support servicesFamilies prepare food for patientHygienic care by family
Facilities may not have capacity to do CBCs, electrolytes, other blood tests
Some do not have running water
RESPONSE
• Treatment of the sick– Humanitarian and public health goals
• Rigorous surveillance– How many ill, ages, where located
• Contact tracing, quarantine and observation• Education/Community engagement• Disposal of the dead• NOT cordon sanitaire
RESPONSE LIMITATIONS
• Country governments poor, lack public health infrastructure, slow sense of
responsibility• Doctors Without Boarders (MSF) cried an
alarm, but without a response• WHO suffered budget cuts – its epidemic
response unit profoundly diminished
INTERNATIONAL RESOURCES
Personnel: Clinical, public health Administrative, logistical
WHO, NGOs, CDC, Faith-based
Personal Protective EquipmentMasks, gloves, impervious gowns, etc., etc.
Equipment for clinical carelabs, beds, IV fluids, etc., etc.
TREATMENT RESEARCH
ZMAPP. Molecular biologic production of 3 antibodies against Ebola
SHOWN TO WORK IN EXPERIMENTAL INFECTIONS In monkeys: all 18 who got 3 infusions survived
3 untreated died
NOT yet shown to work in humans
VACCINE RESEARCH
• GSK/NIH Chimpanzee adenovirus vector that expresses Zaire and Sudan glycoprotein Phase I trial started
• Public Health Agency of Canada/NIH/Walter Reed Vesicular stomatitis recombinant vaccine Phase I trial soon
Please Remember – this is Research
Experimental: No proven therapeutic or preventive effect
Safety in humans: Unknown
If something works: Implementation research Ethical, cross-cultural issues
No magic bullets
WILL EBOLA COME HERE?
Virus has been in labs here for years
High profile patients (Kent Brantly, Nancy Writebol, Rick Sacra)
Ebola candidate patients – show up at Hospital X
Ebola will NOT establish itself in the US
HOSPITALS CAN CARE FOR EBOLA PATIENTS SAFELY
Isolation room
Personal Protective Equipment with Sentinal
Environmental, Waste Disposal, Lab Safety
Mock patient drills, Education
SAFE HOSPITAL CARE
STAT contact with Tennessee Department of Health
Communication and education Media relations
Would be intense
EBOLA IN WEST AFRICANEAR-TERM FUTURE
GrimPredictions up to 20,000+ casesMany MonthsConcern for spread to other West African countries
Food suppliesTransportEconomic/Political destabilization