About Ebola

MUHC preparing

Ebola virus disease (EVD), previously known as Ebola hemorrhagic fever, is deadly disease caused by infection with one of the five know Ebola virus strains. EVD was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of the Congo. Since then, outbreaks have appeared sporadically in Africa. 

The current outbreak:

The current EVD outbreak, first documented in Guinea in March 2014, is the largest and most complex Ebola outbreak ever recorded. In August 2014, the World Health Organization (WHO) Director-General declared the outbreak a Public Health Emergency of International Concern. In October 2014, the number of people infected worldwide passed 10,000 – more than all other EVD outbreaks combined. Click here for the latest update from the WHO.


The incubation period, that is, the time interval from infection with the virus to onset of symptoms is 2 to 21 days. Humans are not infectious until they develop symptoms. First symptoms are the sudden onset of fever fatigue, muscle pain, headache and sore throat. This is followed by vomiting, diarrhoea, rash, symptoms of impaired kidney and liver function, and in some cases, both internal and external bleeding (e.g. oozing from the gums, blood in the stools). Laboratory findings include low white blood cell and platelet counts and elevated liver enzymes. 


EVD spreads through human-to-human transmission via direct contact (through broken skin or mucous membranes) with the blood, secretions, organs or other bodily fluids of infected people, and with surfaces and materials (e.g. bedding, clothing) contaminated with these fluids.

Healthcare workers have frequently been infected while treating patients with suspected or confirmed EVD. This has occurred through close contact with patients when infection control precautions are not strictly practiced.

People remain infectious as long as their blood and body fluids, including semen and breast milk, contain the virus. Men who have recovered from the disease can still transmit the virus through their semen for up to 7 weeks after recovery from illness.


EVD causes an acute, serious illness which is often fatal if untreated. The average case fatality rate is around 50%; rates have varied from 25% to 90% in past outbreaks. Early supportive care, involving rehydration with oral or intravenous fluids, and treatment of specific symptoms, improves survival. There is, as yet, no licensed treatment proven to neutralise the virus but a range of potential treatments, including blood products, immune therapies and drug therapies are currently being evaluated. There are currently no licensed vaccines for EVD but two potential candidates are undergoing evaluation.

Source: Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO)