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

USA

EBOLA INFLUENZAOld – annualConventionalKnownOften deadly5-20% infected annually200,000 hospitalized~32,000 deathsWash handsAvoid coughersGet vaccinated!

NewMysteriousUnknownDeadly0 infected3 hospitalized0 deathsNo sense of personal control