Download "Ebola virus disease - Transmission through body fluids

Ebola virus disease - Transmission
through body fluids; perspectives from
outbreak response in Liberia
Dr Margaret Fitzgerald
Public Health Medicine
Ebola
Filoviridae
• Ebolavirus – 5
viruses/species
–
–
–
–
–
Ebola (Zaire)
Sudan
Bundibugyo
Tai Forest
Reston
• Marburgvirus (single species)
• Cuevavirus
2
Host - ? Fruit bat
• Any of these can infect humans
• Once a human is infected, human-tohuman transmission occurs
How are humans infected?
• Human-to-human
transmission
– Direct contact with blood or
secretions of infected people,
including urine, faeces, vomit, spit,
sweat, semen and breast milk
– Exposure to objects or
environment contaminated with
infected secretions
– Burial ceremonies through direct
contact with the body
• Access through mucosal surface /
breaks in skin / parenteral
• Healthcare workers must practice
strict infection prevention and
control precautions
5
Human-to-Human
Transmission
Ebola is transmitted
through:
– Touching body fluids of a
person who is sick with or
has died from Ebola,
– Touching or using objects
contaminated with Ebola
– But is it actually sexually
acquired ?
– Knowledge mostly from studies of
semen
•
Ebola Transmission
Assessment of the Risk of Ebola Virus Transmission from Bodily Fluids and
Fomites. S142 • JID 2007:196 (Suppl 2) • Bausch et al.
–
–
–
Clinical specimens from 26 lab confirmed cases of Ebola plus environmental
specimens collected from isolation ward, for presence of EBOV.
Virus was detected by culture and/or PCR 16 / 54 clinical specimens (including saliva,
stool, semen, breast milk, tears, nasal blood, and a skin swab) and in 2/ 33
environmental specimens.
Conclusion : EBOV is shed in a wide variety of bodily fluids during the acute period of
illness but that the risk of transmission from fomites in an isolation ward and from
convalescent patients is low when currently recommended infection control
guidelines for the viral hemorrhagic fevers are followed.
•
http://jid.oxfordjournals.org/content/196/Supplement_2/S142.full
•
http://www.livescience.com/47218-ebola-transmission-routes.html
•
http://www.cdc.gov/vhf/ebola/transmission/human-transmission.html
•
•
Review Evidence and understanding of Ebola virus transmission is based on
epidemiologic and laboratory data, summarized below, including investigations of >20
African outbreaks since 1976.6
Sexual transmission of Marburg virus (but not Ebola virus) has been described36
•
http://www.cdc.gov/vhf/ebola/transmission/index.html?s_cid=cs_4053
•
Virus culture and reverse-transcription polymerase chain reaction (RT-PCR) results from 54
clinical samples collected from 26 patients with laboratory-confirmed Ebola hemorrhagic
fever.
Bausch D G et al. J Infect Dis. 2007;196:S142-S147
© 2007 by the Infectious Diseases Society of America
Signs and Symptoms
• Signs generally 2-21 days after contact
with a person who is sick with Ebola
– Most commonly 1-2 weeks, mean 11.4 days
• People who do not show signs of
disease cannot spread the disease
• Also people ill with Ebola ?
• Likely to be able to have sex?
Ebola Virus – typical path through a human being
Note:
On day 7-9 gastrointestinal symptoms can occur; vomiting, diarrhoea and abdominal pain
10 failure: 6-16 days
Death from hypovolemic shock and multiorgan
Liberia
MAJOR CHRONOLOGICAL EVENTS
17th March 2014: Reports from Lofa County Health Officer of 2
suspected cases of hemorrhagic fever in Foya
21 March 2014: EVD was Laboratory confirmed in Guinea
22nd March 2014: Joint MOH-WHO team to Foya for investigation and
response
24th March 2014: NTF is established
30th March 2014: EVD confirmed in Liberia
1st April 2014: Joint MOH-WHO investigation team ( including Chief
Medical Officer, MOH and WR) travel to Lofa
25th May 2014: Onset of 2nd wave of EVD outbreak (no case reported
between 10 April and 24th May)
30th July 2014: President Launches National EVD Response Plan
August Quarantine in City
12
Aug- Sept Humanitarian crisis declared WHO ROAD MAP
Liberia case Investigation in community with
EPI Questionnaire (3-4 pages)
Early MOH-WHO Treatment unit
Ebola Treatment Unit (ETU)
Patient Register
Book
Laboratory
1st test can be
negative in
early days of
illness; need to
repeat
Test for
recovery –
sequential
tests
Convalescence
virus in semen
Burial
Had to design new EPI form for
cremations/ burials
Survive and advice
Convalescence
• Virus can continue to be found in semen
for seven weeks after recovery from the
disease
• Sexual transmission of Ebola not
definitively established, studies shown that
the virus can persist in semen for longer
than in blood or other body fluids hence
advice re condom and abstention
Recovery and Stigma
• India man detained at Delhi airport post recovery as
semen tests positive Nov. 10, carried documents from
Liberia confirming he had successfully undergone Ebola
treatment and had been declared free of any symptoms,
the health ministry said.
• He was placed in quarantine as a precautionary
measure as authorities tested his blood over the next
several days.
• Although his blood tests were clear, authorities decided
to test his semen before releasing him from quarantine.
Those tests showed traces of the virus.
How EVD outbreak has grown
since March 2014
Source: http://www.telegraph.co.uk/
Acknowledgements
• Adapted from materials produced by:
– Darina O Flanagan HPSC
– Dr Orla Condell and Nadine Zeitleman
EuPHEM and EPIET WHO Goarn
– World Health Organisation (WHO)
– Centers for Disease Control and Prevention
(CDC)
– Nigerian Centre for Disease Control and
Prevention
– Public Health England
– Dr Todd F Hatchette, Nova Scotia, Canada
More Information
• Health Protection Surveillance Centre
http://www.hpsc.ie/News/MainBody,14571,en.html
• CDC
http://www.cdc.gov/vhf/ebola/index.html
• WHO
http://www.who.int/csr/disease/ebola/en/
• HSE
http://www.hse.ie/eng/services/Campaigns/Ebolaupdate.
html