Ebola virus disease for health professionals

Ebola virus disease (EVD) is caused by an Ebola virus, of which there are five species. EVD is also known as Ebola, and was previously called Ebola haemorrhagic fever. EVD is a type of viral haemorrhagic fever (VHF), which are life threatening infections whose symptoms can include fever and bleeding. The death rate of EVD depends on the species. For Zaire species of Ebola virus it is estimated to be between 50% and 90%.

Outbreaks of EVD in humans have occurred only in Africa, specifically in, the Democratic Republic of Congo, Gabon, the Sudan, South Sudan, Uganda, Guinea, Sierra Leone, Liberia and Nigeria. There has never been a case in Australia.

EVD is a quarantinable disease under the Australian Quarantine Act 1908 and a notifiable and controlled notifiable disease under the South Australian Public Health Act 2011. This permits the relevant authorities to take appropriate measures, such as requiring isolation of confirmed or suspected cases and quarantine of contacts, to prevent the establishment or spread of EVD in Australia.

Clinical presentation

Sudden onset of an influenza-like illness symptoms including:

  • fever
  • myalgia
  • fatigue
  • headache.

The patient may subsequently develop:

  • gastrointestinal symptoms such as vomiting and diarrhoea
  • neurological symptoms such as confusion and coma
  • vascular symptoms such as conjunctival injection, postural hypotension and oedema
  • maculopapular rash
  • respiratory symptoms such as a sore throat and cough
  • prostration.

After one week, patients may develop a septic shock-like syndrome and progress to multi-organ failure, sometimes accompanied by profuse internal and external bleeding.

Mode of transmission

Ebola virus is introduced into the human population through close contact with the blood, secretions, organs or other bodily fluids of infected animals.

Ebola virus then spreads from person-to-person via contact with the blood, secretions or other bodily fluids of infected people (living or deceased), and indirect contact with environments contaminated with such fluid.

Ebola virus can be spread in healthcare settings where compliance with infection control measures is incomplete, such as: reuse of sharps, use of improperly sterilised equipment or lapses in use of appropriate personal protective equipment.

Ebola virus is not transmitted through casual or remote contact.  Ebola is not spread through aerosols (though caution should be exercised when an aerosol generating procedure is undertaken).

Incubation period

The incubation period ranges from 2 to 21 days, most commonly 8 to 10 days.

Infectious period

People are infectious as long as their blood and secretions contain the virus. Recurrence of symptoms can occur after initial recovery as the virus can persist for long periods in immunologically protected sites, such as the eye. The predominant means of transmission is contact and droplet, although sexual transmission also occurs.

Diagnosis

Consider EVD in patients with:

  • fever (>38°C)

and

  • history of travel to an endemic/epidemic area within 21 days of illness onset OR contact with a confirmed EVD case OR with EVD-infected blood, tissue or objects (for example sharps).

Contact Communicable Disease Control Branch (CDCB) medical officers immediately and seek urgent infectious diseases and/or clinical microbiology advice for any suspected case.

Do not send patients to a pathology collection centre for testing.

Remember, patients returning from affected areas with fever are still more likely to have other causes for their illness, particularly malaria.

Infection control

Patients with suspected or confirmed Ebola will be managed in a quarantine hospital (Royal Adelaide Hospital, Women’s and Children’s Hospital) with enhanced precautions and additional personal protective equipment (PPE) following local protocols.

  • place the patient in a single room with an en-suite bathroom
  • manage with standard and transmission-based precautions, including the use of hand hygiene and appropriate personal protective equipment (PPE) to the level of risk
  • avoid aerosol generating procedures but if absolutely necessary use a N95/P2 mask in a negative pressure room.

See the following fact sheets for management of Ebola virus disease:

Laboratory testing

  • Contact your local infectious diseases team or SA Pathology clinical microbiologist, and CDCB prior to taking any specimens.
  • Routine haematology and other tests should be minimised. Tests required for the immediate management of the patient should only be undertaken in close collaboration with specialist physicians, laboratory staff and the Communicable Disease Control Branch.
  • Ebola virus nucleic acid testing (NAT), also known as PCR, is available through SA Pathology.

Treatment

Supportive care. There is currently no specific treatment for EVD that is proven to be effective.

Notification

The Communicable Disease Control Branch, South Australia, should be notified on suspicion of EVD on 1300 232 272 (24 hours, 7 days) to enable prompt public health follow up.