Ebolavirus disease (EVD) outbreaks in West Africa Summary

Ebolavirus disease (EVD) outbreaks in West Africa
Important information for clinicians in secondary or tertiary care
11 August 2014
Summary
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The largest outbreak of Ebolavirus disease (EVD)1 ever reported is continuing in Guinea,
Liberia and Sierra Leone in West Africa, with probable and suspected cases also reported
from Nigeria.
Regular updates are available from the World Health Organization (WHO) website
(http://www.who.int/csr/don/en/)
As of 6 August 2014, there were 1,779 clinically-compatible cases, of which 1,134 have been
laboratory confirmed, and 961 have died (case fatality rate 54%).
The risk of infection is extremely low unless there has been direct exposure to the bodily
fluids of an infected person (including unprotected sexual contact with confirmed cases up
to seven weeks after they have recovered) or animal (alive or dead).
In patients with clinically-compatible symptoms (see section below, ‘What are the symptoms and
who do I test for EVD?’) with a history of travel or residence in affected areas (see map) in the 21
days prior to symptom onset, or contact with known confirmed or probable cases in the 21 days
before illness onset, the following is recommended:
1. The patient should be placed in a single room, and transmission-based precautions
implemented (contact and droplet), including the use of personal protective equipment
(PPE). A biological safety cabinet should be used in the laboratory.
2. The relevant state/territory public health unit/communicable diseases branch should be
notified promptly of any suspected (and probable or confirmed) cases in order to discuss
and coordinate testing and management of contacts.
3. Blood and other samples should be collected for Ebolavirus testing and for other
investigations, but since blood is highly infectious, routine haematology and other tests
should be minimised. If other tests are required for the immediate management of the
patient, these should only be performed in close collaboration with specialist physicians,
laboratory staff and public health authorities.
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The disease has previously been called Ebola Haemorrhagic Fever, but not all cases are haemorrhagic, and
the WHO has begun referring to it as EVD.
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Map: Areas of Guinea, Liberia and Sierra Leone affected by EVD as of 7 August 2014 (from the CDC
website http://www.cdc.gov/vhf/ebola/resources/distribution-map-guinea-outbreak.html,
accessed 11 August 2014).
What are the symptoms and who do I test for EVD?
The likelihood that a febrile illness in a returned traveller is due to EVD is very low, however
clinicians should be aware of the possibility of EVD in patients who meet the suspected case
definition.
The onset of symptoms is sudden and includes a flu-like illness, fever, myalgia, fatigue, and
headache. The next stage may include symptoms that are gastrointestinal (vomiting, diarrhoea),
neurological (headaches, confusion), vascular, cutaneous (maculopapular rash), respiratory (sore
throat, cough) and can include prostration. After one week, cases may develop a septic shock-like
syndrome, and progress to multi-organ failure, sometimes accompanied by profuse internal and
external bleeding. The case-fatality rate (CFR) for Zaire strain of EVD cases is estimated to be
between 50% and 90%, while for other species, the CFR may be lower.
Testing should be considered for persons with epidemiological and clinical evidence:
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Clinical evidence
A compatible clinical illness as determined by an infectious disease physician. Clinical evidence,
which includes fever of greater than 38 degrees Celsius, and additional symptoms such as
severe headache, muscle pain, vomiting, diarrhoea, abdominal pain, or unexplained
haemorrhage;
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Epidemiological evidence
Epidemiologic risk factors within the past 21 days before the onset of symptoms, such as
contact with blood or other body fluids of a patient known to have or suspected to have EVD;
residence in—or travel to—an area where EVD transmission is active; or direct handling of bats
or primates from disease-endemic areas.*
* Affected areas should currently be considered to be Guinea, Liberia, Nigeria and Sierra Leone, but travel to neighbouring countries
in West Africa (Mali, Cote d’Ivoire, Guinea-Bissau, Senegal (Map)) should also be considered where there is strong clinical suspicion.
Further, filoviruses are endemic in sub-Saharan Africa. It should be noted that the risk of infection is extremely low even in persons
with a compatible travel history, unless there has been direct exposure to the bodily fluids of an infected person (including
unprotected sexual contact with confirmed cases up to seven weeks after they have recovered) or animal (alive or dead).
The treating doctor must notify a suspected case immediately to their state/territory
communicable disease branch/centre to discuss testing and management (see “Who do I contact if
I have a suspected case?” for contact information).
How do I test for EVD?
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In the event of a suspected case, the jurisdictional Public Health Reference Laboratory and
Communicable Disease control branch/Public health Unit should be contacted as soon as
possible for further advice on testing.
Confirmatory testing for EVD in Australia is conducted at the National High Security
Quarantine Laboratory (NHQSL) at VIDRL. Telephone contact with the VIDRL on-call medical
officer is essential before any specimen referral. The VIDRL on-call microbiologist can be
contacted on mobile 0438 599 437. In case of difficulty back-up is provided by the VIDRL oncall laboratory manager (0438 599 439), and the Royal Melbourne Hospital Switchboard (03
9342 7000) if all else fails.
In some jurisdictions suitable facilities exist for the preliminary testing of samples for
Ebolavirus (NSW, QLD). Where preliminary testing is to be conducted at these facilities, the
jurisdictional reference laboratory should forward samples to VIDRL for confirmation.
Where tests for EVD have been ordered, routine haematology and other tests should be
minimised since blood is highly infectious.
If other tests are required for the immediate management of the patient, these should only
be performed in close collaboration with specialist physicians, laboratory staff and public
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health authorities and only in laboratories designated to do this work under jurisdictional
viral haemorrhagic fever plans.
EDTA blood, serum, throat swabs and urine are suitable for testing for Ebolavirus. The
primary diagnostic method is detection of Ebolavirus by PCR in blood, serum, plasma, a
throat swab or urine. Serology is also available.
The receiving laboratory should be notified in advance before specimens are dispatched.
Specimens must be transported to the laboratory in clearly labelled ("Infectious Risk")
appropriate containers (specimen tube within a sealed plastic bag, then within a clear hard
plastic container which has sufficient absorbent material to contain a spill).
Further information is available in a separate advice to laboratories, available from the
Department of Health website
(http://www.health.gov.au/internet/main/publishing.nsf/Content/ohp-evd.htm).
Are health workers at risk from EVD?
In affected African countries, caring for ill relatives is a known risk factor for infection, and
healthcare workers, particularly those in resource poor settings with inadequate infection control
are also at risk.
Infection control recommendations in this document for suspected, probable and confirmed cases
aim to provide the highest level of protection for health care workers, given the current state of
knowledge. Health care workers should follow the contact and droplet precautions in NHMRC:
Australian Guidelines for the Prevention and Control of Infection in Healthcare - 2010 - External
Link (particularly section B2.3).
What are the recommended isolation and PPE recommendations for
patients in hospital?
These recommendations on isolation and PPE for probable and confirmed cases take a deliberately
cautious approach by recommending measures that aim to control the transmission of pathogens
that can be spread by the contact and droplet routes. These measures are detailed in NHMRC:
Australian Guidelines for the Prevention and Control of Infection in Healthcare - 2010 - External
Link (particularly section B2.3). In summary, transmission-based precautions for probable and
confirmed cases should include:
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Placement of confirmed and probable cases in a single room.
Droplet transmission precautions, including routine use of a surgical mask, disposable gown,
gloves, and eye protection when entering a patient care area.
Aerosol generating procedures (AGP) should be avoided in an EVD patient. If an AGP is
essential, transmission-based contact and airborne precautions must be used when
undertaking procedures that may generate aerosols. These are described in NHMRC:
Australian Guidelines for the Prevention and Control of Infection in Healthcare – 2010
(particularly section B2.4), and include the requirement for PPE including the use of gloves,
gowns, P2 (N95) respirators, eye protection and hand hygiene.
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Contact precautions, including close attention to hand hygiene.
Further information on infection control is provided by the WHO, available from the WHO website
(http://www.who.int/csr/bioriskreduction/filovirus_infection_control/en/), and the European
Centre for Disease Control (ECDC) in their Risk Assessment, available from the ECDC website
(http://www.ecdc.europa.eu/en/publications/_layouts/forms/Publication_DispForm.aspx?List=4f5
5ad51-4aed-4d32-b960-af70113dbb90&ID=1068)
Background information
Ebolaviruses
EVD is caused by an Ebolavirus. Ebolaviruses are part of the family Filoviridae, which also includes
Marburg virus. Fruit bats of the Pteropodidae family are considered to be a likely natural host of the
Ebolavirus, with outbreaks amongst other species such as chimpanzees, gorillas, monkeys, forest
antelope from time to time. Five species of Ebolavirus have been identified, namely Zaire, Sudan,
Reston, Tai Forest and Bundibugyo, from samples collected during humans and non-human
primates outbreaks since the first outbreak in the Democratic Republic of the Congo.
Transmission
Ebola is introduced into the human population through close contact with the blood, secretions,
organs or other bodily fluids of infected animals (often therefore through hunting or preparation of
"bushmeat"). Ebolavirus then spreads through person-to-person transmission via contact with the
blood, secretions, organs or other bodily fluids of infected people, and indirect contact with
environments contaminated with such fluid, including in healthcare settings. The risk for infection
in healthcare settings can be significantly reduced through the appropriate use of infection control
precautions and adequate barrier procedures. Transmission through sexual contact may occur up
to seven weeks after clinical recovery. Airborne transmission, as occurs for measles or smallpox,
has never been documented. Simple physical contact with a sick person appears not to be sufficient
for contracting EVD. Transmission through heavily contaminated fomites is apparently possible.
Traditional burial ceremonies in affected areas of Africa are a known high risk activity for
transmission.
Incubation period
The incubation period varies from 2 to 21 days.
Treatment
There are no specific prophylactic (vaccine) or therapeutic (antiviral drugs) options available to
treat human infections, and care is largely supportive.
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Quarantinable disease
EVD is a quarantinable disease in Australia, and as such can be controlled and eradicated through a
range of quarantine measures, including enforcing appropriate quarantine measures if suspected
cases of disease are identified.
Situation update
See the WHO website (http://www.who.int/csr/don/en/) for the latest information
Guinea
As of 6 August 2014, the Ministry of Health of Guinea had reported a total of 495 clinically
compatible cases, including 367 deaths (case-fatality rate, CFR 73%), of which 355 tested positive
by PCR.
Liberia
As of 6 August 2014, the Ministry of Health and Social Welfare (MOHSW) of Liberia had reported a
total of 554 clinical cases of EVD, including 294 deaths (CFR 53%) of which 148 cases tested positive
by PCR.
Nigeria
As of 6 August 2014, the Ministry of Health in Nigeria had reported 13 clinical cases of EVD (seven
probable and six suspected), including two deaths. None of the cases have been confirmed.
Sierra Leone
As of 6 August 2014, the Ministry of Health and Sanitation of Sierra Leone had reported a total of
717 clinically-compatible cases including 298 deaths (CFR 42%), of which 631 tested positive by
PCR.
Further advice
Surveillance case definition for confirmed and probable cases, available from the Department of
Health website (http://www.health.gov.au/internet/main/publishing.nsf/Content/cda-surveilnndss-casedefs-cd_vhf.htm)
WHO Interim Infection Control Recommendations for Care of Patients with Suspected or Confirmed
Filovirus (Ebola, Marburg) Haemorrhagic Fever available from the WHO website
(http://www.who.int/csr/bioriskreduction/filovirus_infection_control/en/)
WHO situation updates http://www.who.int/csr/disease/ebola/en/
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WHO Fact Sheet on Ebolavirus disease http://www.who.int/mediacentre/factsheets/fs103/en/
WHO AFRO updates http://www.afro.who.int/en/clusters-a-programmes/dpc/epidemic-apandemic-alert-and-response/outbreak-news.html
Reporting
The treating doctor must notify a suspected case immediately to their state/territory
communicable disease branch/centre to discuss testing and management of contacts (see “Who do
I contact if I have a suspected case?” for contact information).
Confirmed and probable cases must be reported to state/territory public health authorities
immediately on being classified as such. State and territory authorities should notify the
Commonwealth Department of Health about suspected, probable and confirmed cases.
Advice for contacts of cases
Contacts of cases should be directed to your state/territory communicable disease branch/centre
for advice.
Who do I contact if I have a suspected case?
Contact your state/territory communicable disease branch/centre.
ACT
(02) 6205 2155
NSW
1300 066 055
Contact details for the public health offices in NSW Area Health Service Areas
(www0.health.nsw.gov.au/publichealth/Infectious/phus.asp)
NT
(08) 8922 8044
Queensland
13 432 584
Contact details for the public health offices in QLD Area
(www.health.qld.gov.au/cdcg/contacts.asp)
SA
1300 232 272
Tasmania
1800 671 738
Victoria
1300 651 160
WA
(08) 9388 4801 After hours (08) 9328 0553
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Contact details for the public health offices in WA
(www.public.health.wa.gov.au/3/280/2/contact_details_for_regional_population__public_he.pm)
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