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Ebola Virus
The Clinical Excellence Commission
November 2014
What is a Filovirus
• Family called Filoviridae - cause severe
haemorrhagic fever in humans and nonhuman primates.
• Two members of this virus family: Marburg
virus and Ebola virus.
• Four species of Ebola virus: Ivory Coast,
Sudan, Zaire, and Reston.
• Ebola-Reston does not cause severe disease
in humans; however, it can be fatal in
monkeys.
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What is a Filovirus
• Filovirus virions (complete viral particles) may
appear in several shapes - include long,
branched filaments as well as shorter
filaments shaped like a "6", a "U", or a circle.
• Viral filaments are enveloped in a lipid (fatty)
membrane.
• Each virion contains one molecule of singlestranded, negative-sense RNA.
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What is a Filovirus
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The History of Filoviruses
• The first filovirus was recognized in 1967
when a number of laboratory workers in
Germany and Yugoslavia, who were handling
tissues from green monkeys, developed
haemorrhagic fever.
• A total of 31 cases and seven deaths were
associated with these outbreaks. The virus
was named after Marburg, Germany, the site
of one of the outbreaks.
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The History of Filoviruses
• Ebola virus first identified in 1976 in northern
Zaire (Democratic Republic of Congo) and
southern Sudan.
• The outbreaks involved what eventually
proved to be two different species of Ebola
virus; both were named after the nations in
which they were discovered.
• Both viruses showed themselves to be highly
lethal, as 90% of the Zairian cases and 50% of
the Sudanese cases resulted in death.
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Spread
• Just how the virus is transmitted from the
natural reservoir to a human is unknown.
• Hard to catch - Human to human transmission
through direct contact with body fluids and
indirect contact through body fluids such as
unsterilized equipment.
•
Entry points – mucous membranes, cuts &
abrasions
• Easy to catch – infective dose 1-6 virus particles
• Importance of Personal Protective Equipment (PPE)
• Not infectious before symptoms
Viral Haemorrhagic Fevers
Virus
Lassa
Ebola
Marburg
Crimean-Congo
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•
•
•
Incubation period
6 – 21 days
6 - 21 days (8 – 10 days)
3 – 10 days
1 – 12 days
Fever and malaise
Vomiting and diarrhoea
Bruising, rashes and bleeding
High case fatality rates
Presenting Symptoms (2)
• Starts with sudden onset fever, malaise,
myalgia & headache
• Pharyngitis, vomiting, diarrhoea and maculopapular rash
• Haemorrhage & shock in 2nd week
• (50% no haemorrhagic manifestations)
• Death 6 – 16 days after onset
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Presenting symptoms (44/106)
Symptom
Fever
Headache
Weakness
Dizziness
Diarrhoea
Abdominal pain
Sore throat
Vomiting
Conjuctivitis
Percentage
89%
80%
66%
60%
51%
40%
34%
34%
31%
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Symptoms associated with death
•
•
•
•
44 patients
Weakness
Dizziness
Diarrhoea
(P = 0.003)
(P = 0.01)
(P = 0.04)
• Diarrhoea on presentation had 94% mortality
rate compared with 65% for no diarrhoea
• Only one patient had haemorrhagic features
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Fatal cases
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Fatal symptoms
on presentation
Pathogenesis
West African Outbreak 2014 - CDC
2014 Outbreak
• Countries : Guinea, Sierra Leone, Liberia, and
Mali (new). Nigeria & Senegal(now clear)
• Cases as at 2/11/14
• Cases – 13042
• Deaths – 4818 (~37% case fatality rate)
• Also in USA, Spain, - infected in West Africa or
while caring for patients
• Democratic Republic of Congo - unrelated
Putting into Perspective
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Treatment
• Supportive
• Fluids, blood, symptom management
• ICU
• Vaccine
• difficult due to mutations
• Canadians success in 4 monkeys
• Drugs
• Some experimental - ZMapp
Prevention
Spread in West Africa
– Larger populations than previous outbreaks
– More communications and movement
– 10 year civil war in Sierra Leone – refugees
– Poor medical infrastructure – distrust of Western
medicine
– Malnutrition
– Access to clean water and sanitation
– Local customs – burial practices
Prevention (2)
Identify possible infected persons
– Airport temp. screening – not effective
– Algorithm
Ebola – NSW Roles
• NSW Ministry of Health - Health Protection
Unit are the lead agency.
• PHUs provide advice and support to facilites.
• CEC support role – advice
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•
•
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Infection prevention and control in hospitals
PPE
Environmental Cleaning
Waste management
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NSW CONTINGENCY PLAN FOR
VIRAL HAEMORRHAGIC FEVERS
Health Protection NSW
Email: [email protected]
Phone: (02) 9391 9195
Last updated 22 October 2014
http://www.health.nsw.gov.au/Infectious/alerts/Do
cuments/NSW-VHF-Plan-Web.pdf
Prevention (3)
• Isolation of infected persons – quarantine
• New Act in NSW – reportable by MO
• Quarantine
• Disinfection of contaminated surfaces –
bleach
• Personal Protective Equipment (PPE)
• VHF isolation precautions is currently the
centerpiece of control.
Future of Ebola outbreak
• Outbreak uncontrolled
• If not controlled - millions of infected individuals
• Australia – from overseas, PPE breakdown
• Mutation
• Airborne virus – highly unlikey to change mode of
transmission
• Decreased severity – more problematic ???
• Other potential strains
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Thank you
Questions
For further information:
http://www.health.nsw.gov.au/infectious/alerts/pages/EVD.aspx
www.cec.health.nsw.gov.au
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