Ebola Haemorrhagic Fever

May 2005

Know before you go!

Infectious diseases not necessarily common in Canada can occur and may even be widespread in other countries. Standards of hygiene and medical care may differ from those at home. Before departure, you should learn about the health conditions in the country or countries you plan to visit, your own risk of disease and the steps you can take to prevent illness.

The risk is yours
Your risk of acquiring a disease depends on several factors. They include: your age, gender, immunization status and current state of health; your itinerary, duration and style of travel (e.g., first class, adventure) and anticipated travel activities (e.g., animal contact, exposure to fresh water, sexual contact); as well as the local disease situation.

Risk assessment consultation
The Public Health Agency of Canada strongly recommends that your travel plans include contacting a travel medicine clinic or physician six to eight weeks before departure. Based on your individual risk assessment, a health care professional can determine your need for immunizations and/or preventive medication (prophylaxis) and advise you on precautions to avoid disease.

Some facts from the experts
The information below has been developed and is updated in consultation with The Public Health Agency of Canada's Committee to Advise on Tropical Medicine and Travel (CATMAT). The recommendations are intended as general advice about the prevention of Ebola viral haemorrhagic fever for Canadians travelling internationally.

Disease profile

Ebola haemorrhagic fever (EHF) is a severe and acute, often-fatal, haemorrhagic viral disease in humans and non-human primates (monkeys, gorillas and chimpanzees). Caused by the Ebola virus, of the family Filoviridae, EHF causes death in 50 - 90% of all clinically ill cases. It occurs in sporadic outbreaks, often centred in health care settings in developing countries, where social and economic conditions often favour the spread of the virus.

EHF is named after the Ebola River in The Democratic Republic of Congo (formerly Zaire), where it was first identified in 1976. Three of the four strains of the Ebola virus (Ebola-Zaire, Ebola-Sudan and Ebola-Ivory Coast) have been associated with human disease. The fourth strain, Ebola-Reston, is associated with fatal haemorrhagic disease in nonhuman primates (monkeys and chimpanzees). It was discovered in 1989 in the United States following an outbreak of viral haemorrhagic fever among monkeys imported from the Philippines to Reston, Virginia.

Transmission

It is unknown how the first human case (i.e., index case) of Ebola infection in any outbreak occurs. Some researchers believe the virus is animal-borne (i.e., zoonotic), among non-human primates (monkeys, gorillas and chimpanzees) native to Africa and Asia, suggesting that the first human case occurs following contact with an animal. Other researchers suggest that Ebola's origin is a plant virus that subsequently caused infection in animals. (Based on laboratory tests indicating that some bat species can withstand infection without fatalities, there is speculation that bats may play a role in the virus's life cycle.

We do know that the Ebola virus can be transmitted in several ways, the most significant being person-to-person through direct contact with body fluids (e.g., blood, semen, vaginal fluid) of an infected person. The risk of transmission is high for health-care providers, family members of an infected individual and others in a health-care setting where contact with body fluids is frequent and sterilization of equipment may be unreliable. Transmission may occur through pregnancy and sexual activity. Studies show that transmission through semen may occur up to seven weeks after an individual has recovered from the virus. Risk is also high for family and others having direct contact with the infected body of a deceased individual during burial ceremonies. Transmission of the Ebola virus has also occurred in those handling ill or dead infected chimpanzees.

Geographic distribution and incidence trends

The Ebola virus' precise geographic origin remains unknown, but it is thought to be centred in the rain forests of Africa and Asia. In total, approximately 1,850 cases with over 1,200 deaths have been documented since 1976.

Since its discovery, the Ebola virus has been identified in the following countries.

Countries where virus occurs

Year	Country	Virus subtype	Cases	Deaths
1976	Sudan	Ebola-Sudan	284	151
1976	Zaire (DRC)	Ebola-Zaire	318	280
1977	Zaire (DRC)	Ebola-Zaire	1	1
1979	Sudan	Ebola-Sudan	34	22
1994	Gabon	Ebola-Zaire	52	31
1994	Côte d'Ivoire	Ebola-Côte d'Ivoire	1	0
1995	Liberia	Ebola-Côte d'Ivoire	1	0
1995	Democratic Republic of Congo (formerly Zaire)	Ebola-Zaire	315	250
1996 (Jan - April)	Gabon	Ebola-Zaire	37	21
1996 - 1997 (July - Jan)	Gabon	Ebola-Zaire	60	45
1996	South Africa	Ebola-Zaire	1*	1
2000 - 2001	Uganda	Ebola-Sudan	425	224
2001 -2002 (Oct 01 - March 02)	Gabon	Ebola-Zaire	65	53
2001 -2002 (Oct 01 - March 02)	Republic of Congo	Ebola-Zaire	59	44
2002 - 2003 (Dec02 - April 03)	Republic of Congo	Ebola-Zaire	143	128
2003 (Nov - Dec)	Republic of Congo	Ebola-Zaire	35	29
2004	Sudan	Ebola-Sudan	17	7
Total			1848	1287
Source, World Health Organization

Symptoms

The incubation period of the Ebola virus ranges from 2 to 21 days. EHF symptoms often begin abruptly, with the sudden onset of high fever, weakness, muscle pain, headache and sore throat. This is quickly followed by more severe symptoms including vomiting, diarrhea, rash, decreased kidney and liver functioning, and in some cases, both internal and external bleeding. Specific laboratory blood tests can confirm diagnosis.

Treatment

There is no standard treatment yet available for Ebola haemorrhagic fever. M anagement of individuals with Ebola focuses primarily on comfort and supportive measures, especially rehydration to replenish fluids and electrolytes lost through vomiting and diarrhea. Efforts should be made to prevent the spread of infection.

Prevention and personal precautions

There is currently no vaccine that protects against the Ebola virus. Education regarding infection control measures to prevent the spread of the virus is paramount.

Recommendations

Unless you are travelling to an area where an Ebola outbreak is occurring and you have direct contact with an ill individual infected with Ebola, the Public Health Agency of Canada advises that the risk of acquiring Ebola virus is extremely low.

Health-care professionals or lay individuals travelling to an Ebola virus outbreak area and who are providing care for ill individuals, should avoid any exposure to blood and bodily fluids and be fully informed on guidelines for routine practice for infection control and be fully informed about how to reduce direct exposure to bodily fluids (e.g., blood, semen, vaginal fluids, organs).

Some things to think about...

While your chance of acquiring the Ebola virus is very low, if you develop a fever with skin rash or bleeding while in, or after leaving, an Ebola-outbreak area where you have cared for a sick person(s), seek medical attention immediately and report your travel history.

For more information...

• For brief disease information on Ebola, visit the World Health Organization Ebola Fact Sheet.
• For travel medicine professionals, visit the Committee to Advise on Tropical Medicine and Travel (CATMAT) statement on "Fever in the International Traveller: Initial Assessment Guidelines".
• For more Know before you go! information click here.

For Health Care Professionals, visit…

• "Infection Control for Viral Haemorrhagic Fevers in the African Health Care Setting" published by The Democratic Republic of Congo's Ministry of Health, the World Health Organization, and the Centers for Disease Control and Prevention.