A comprehensive yet crisp primer on Ebola virus and its public health relevance.

1. Ebola Virus Disease (EVD)
Dr. Rizwan S A, M.D.,
Department of Community Medicine,
VMCH&RI, Madurai,
“Got no time for wild polemics, hung up on epidemics” – Anonymous

2. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
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3. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
Rizwan SA, VMCHRI

4. Why learn about EVD?
 Limited scientific understanding
 Highly fatal disease
 Causes large outbreaks
 Difficult to contain
 No proven treatment or vaccine
 A pandemic threat
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5. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
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6. A story – 1/3
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7. A story – 2/3
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8. A story – 3/3
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9. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
Rizwan SA, VMCHRI

10. Epidemiological aspects
 Natural host - Fruit bats of
Pteropodidae family
 Reservoir – fruit bats
 Sources – bush meat, NHP,
Infected humans, fomites
 Incubation period – 2 to 21 days
 Communicability – high, virus
isolated after 90 days of recovery
 Case fatality – 50 to 90%
 Immunity – long term not
proven, deceased patients failed
to produce immune response
 No. of outbreaks – >30
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11. Geographic distribution – 1/2
 First outbreak occurred in
Zaire (Congo) in 1976
 Followed by several
outbreaks, all in Africa
(except one in Philippines,
Italy, USA)
 Latest on-going outbreak in
west Africa started in
March 2014 in Guinea
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12. Geographic distribution – 2/2

13. Modes of transmission
 Direct contact (through broken skin or mucous
membranes) with
 a sick person's blood or body fluids (urine, saliva, faeces,
vomit, semen)
 objects (such as needles) that have been contaminated with
infected body fluids
 infected animals
 High risk groups – bush meat hunters, forest dwellers,
health workers, relatives of patients, funeral attendees,
corpse handlers, lab personnel
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14. Transmission cycle
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15. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
Rizwan SA, VMCHRI

16. Virological
aspects
• Family Filoviridae in the order
Mononegavirales
• Five species
• Zaire, Sudan, Taï, Reston,
Bundibugyo
• Enveloped, non-segmented,
negative-strand RNA virus,
filamentous
• Genes arranged linearly
coding for seven structural
proteins - NP, VP35, VP40, GP,
VP30, VP24 and L with NP
• GP, transmembrane protein
and responsible for receptor
binding and membrane
fusion
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17. Clinical features
• Range from minor viral illness
to fatal haemorrhagic fever
• Ebola haemorrhagic fever
(Ebola HF) is type of Viral
Haemorrhagic Fevers
• Most common constellation
of symptoms is together
called Ebola Virus Disease
• EVD – duration 2 to 20 days,
fever, nausea, vomiting, non-bloody
diarrhoea, abdominal
pain, conjunctivitis,
weakness, severe headache
and myalgia
• E. Hemorrhagic fever -
hematemesis, epistaxis,
increased postpartum
bleeding, bleeding gums etc.,
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18. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
Rizwan SA, VMCHRI

19. Diagnosis
 CDC case definitions
 Person Under Investigation
 Probable case
 Confirmed case
 Non-case
 Exposure risk levels
• In early phase - Antigen-capture
ELISA, IgM ELISA,
PCR, Virus isolation
• In later phase - IgM and IgG
antibodies
• In deceased patients –
immunohistochemistry, PCR,
virus isolation
• Strict precautions during
transportation of samples
and all testing in BSL-4 lab
• Differentials – Lassa fever,
malaria, shigellosis, cholera,
leptospirosis, plague,
rickettsiosis, relapsing fever,
other viral haemorrhagic
fevers
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20. Treatment  Experimental treatments
 ZMapp – a combo of 3 monoclonal
antibodies
 TKM-Ebola – targets RNA of the
virus
 MB-2003 - prevents infection in
mice and non-human primates
when administered as post-exposure
prophylaxis within one to
two days
 BCX-4430 – RNA polymerase inh
 Favipiravir, AVI 7288
 Whole blood and convalescent
serum transfusion from recovered
patients
• No proven antiviral drug
• Symptomatic treatment only
• Providing intravenous fluids
and balancing electrolytes
(body salts)
• Maintaining oxygen status
and blood pressure
• Treating other infections if
they occur
• Barrier-nursing techniques
• Personal Protective
Equipment
• Infection control measures
• Isolation of Ebola patients
from contact
Rizwan SA, VMCHRI

21. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
Rizwan SA, VMCHRI

22. Control measures – 1/5
 Public health measures - early
detection and isolation, contact
tracing and rigorous infection
control measures
 Screening of travellers from
affected countries in airports,
seaports and land borders
 Quarantine and observation of
suspected cases for 21 days from
exposure
 Awareness generation among
people, removing misconceptions
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23. Control measures – 2/5
 All suspected or confirmed cases, single
closed patient room
 Avoiding contact
 A log book containing details of persons
entering
 Personal protective equipment for
caretakers
 Dedicated medical equipment
 Minimum use of sharps
 Disinfection of samples - heating to 60°C
for one hour, in 3% acetic acid
 Only BSL 4 lab should handle samples
 Hospital monitoring policy for staff
In this 2014 photo provided by the Samaritan's Purse aid organization, Dr. Kent Brantly, left, treats an Ebola patient at the Samaritan's Purse Ebola Case Management
Center in Monrovia, Liberia. On Saturday, July 26, 2014, the North Carolina-based aid organization said Brantly tested positive for the disease and was being treated at a
hospital in Monrovia.
View of an isolation center for people infected with Ebola at Donka Hospital in Conakry. Rizwan SA, VMCHRI 25/35

24. Control measures – 3/5
 Vaccines
 Virus like particles: ZEBOV (VP40, CG and NP)
 Non-replicating vectors: alpha virus, DNA vaccines, recombinant adenovirus based
vectors (rAD)
 Replication competent vectors: Recombinant Paramyxovirus-based vectors,
Recombinant vesicular stomatitis virus-based vectors (rVSV), Recombinant rabies
virus based (rRABV)
 The first vaccine platform that successfully protected NHPs from Ebola virus infection
was a recombinant adenovirus serotype 5(rAd5) vector
 Latest - chimpanzee-derived replication-defective adenovirus (ChAd) vaccine
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25. Control measures – 4/5
 Social aspects
 Cultural practices – burial rituals
 Illiteracy and lack of awareness
 Fear of modern medicine, equipment
 False rumours and misinformation
 Ethical issues of giving experimental treatment
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26. Control measures – 5/5
 International cooperation
 CDC, WHO, European Mobile Laboratory (EMLab) Project, African
Union
 Voluntary agencies - MSF, Samaritan’s Purse
 Staff, Outbreak response teams, lab experts, doctors, equipment,
gloves, medicines, disinfectants
 Research for medicines and vaccines
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27. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
Rizwan SA, VMCHRI

28. Challenges to control
 Lack of effective treatment and vaccine
 Weak public health infrastructure, manpower, weak labs
 Poverty and Illiteracy
 Lack of political stability
 Delayed international response
 Failure to anticipate and incorporate social aspects
 Funding problems
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29. Outline
 Why learn about EVD?
 History
 Epidemiology
 Virological and clinical aspects
 Management
 Control measures
 Challenges
 Pandemic threat
Rizwan SA, VMCHRI

30. Pandemic threat
 None of the past outbreaks have developed into a pandemic
But,
 2014 outbreak – As of August 31, 2014, 3707 cases and >1800
people dead across 5 countries
 WHO’s declared ‘Public Health Emergency of International Concern’
in August 2014
 Attack rate - 12.6 cases per 10,000 inhabitants, Ro is 2.7
 No population level immunity
 Bioterrorism
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31. Take home messages
 Ebola is an new and emerging infection
 Ability to cause large outbreaks with high casualty
 In the absence of proven treatments, prevention is the
main weapon
 Social aspects are very important in control
 Simple and established PH measures are sufficient
 A potential pandemic
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32. Home work
 Group 1 - Learn the principles of outbreak investigation –
watch the movie ‘Contagion’ and write a one page
summary
 Group 2 - A one page summary on conditions needed to
declare a pandemic
 Group 3 - A one page summary of how India is planning
to respond to this threat, the agencies involved and your
ideas for preparedness in our hospital
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33. Reference materials
 CDC website http://www.cdc.gov/vhf/ebola/about.html
 WHO website http://www.who.int/csr/disease/ebola/en/
 The Lancet Ebola Resource Centre
http://ebola.thelancet.com/
 Journals - Bulletin of the WHO, NEJM and BMJ, August and
September 2014 issues
 Image courtesy – bbc.co.uk, google images, CDC and WHO
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34. Thank You