What is Ebola?
Ebola is a disease is caused by a virus in the family "Filoviridae". Viruses in this family are very large and have several long filaments or tails. Unlike small viruses, such as influenza virus, Ebola virus cannot easily pass from person to person in the air and cannot survive for very long on surfaces outside of the body.
Ebola virus causes a severe disease called haemorrhagic fever. A haemorrhagic fever is one that involves damage to the blood vessels, loss of white blood cells and platelets, low blood pressure, and shock.
There are other diseases and other haemorrhagic fevers that present the same symptoms as the Ebola virus disease. Medical tests are required to confirm an Ebola diagnosis.
The World Health Organization (WHO) states that the average case fatality rate is around 50%. Rates have varied from 25% to 90% in past outbreaks.
How does the Ebola virus spread?
Ebola virus is spread by direct contact with body fluids of an infected person or a recently deceased person (e.g., blood, saliva, feces, vomit) or from infected animals. The virus can enter your body through breaks in your skin (e.g., a cut), or through your eyes, nose or mouth. The Ebola virus also spreads by contact with equipment that has been contaminated by infected body fluids, such as needles.
Ebola is not spread through the air (i.e., it does not spread like the seasonal flu virus), nor is it spread by mosquitoes or water. Walking by an infected person is not enough contact to spread the disease. There is no indication that Ebola is spread by casual contact with surfaces touched by an infected person.
The amount of virus in the body of an infected person becomes significant at the time that symptoms of the illness first appear. The person must be showing symptoms of illness in order to spread the disease. During the incubation period (the time before symptoms become evident), no cases of Ebola being transmitted have been reported.
What is the risk of becoming infected by the Ebola virus?
In Canada and in any area where there is not an outbreak, the risk of infection for the general population (people not in direct contact with symptomatic persons) is extremely low. The key risk factors are being in areas of an outbreak, or participating in activities that put a person at risk (e.g., workers caring for Ebola patients).
What are the symptoms of Ebola?
Symptoms can begin 2 to 21 days after exposure. The average period for symptoms to appear is 8 to 10 days. Initial symptoms include:
- Sore throat.
- Muscle pain and weakness.
Additional symptoms include:
- Nausea, vomiting and diarrhea.
- Haemorrhaging (bleeding from inside and outside the body).
Who might be exposed to the Ebola virus?
As mentioned above, the risk of exposure outside an area where there is an outbreak is very low. Persons in health care or emergency response who may come in contact with the infected bodily fluids are at some risk. Other situations where exposure may possibly occur outside an affected area include airline crews, servicing and cargo employees, laboratory workers, mortuary and death care workers, and customs/border protection.
What prevention steps can be taken?
The U.S. Occupational Safety and Health Administration (OSHA) lists interim general guidance for workers who are in a known or reasonably suspected environment where they may contact the Ebola virus (e.g., there is known contamination by potentially infectious materials). OSHA's recommendations include:
- Follow good infection control practices.
- Meet applicable requirements for personal protective equipment (PPE) and respirators. Care must be taken to put on and remove PPE properly.
- Wear gloves, use good handing washing techniques after removing gloves, and dispose of gloves in properly labelled containers.
- If you might be splashed, sprayed or spattered with body fluids, wear face and eye protection such as full-face shield or surgical masks with goggles. Aprons or other fluid-resistant clothing must also be worn.
- If you are asked to clean a surface that may be contaminated, your employer is responsible for ensuring you are protected and that appropriate procedures are followed.
- Training about the sources of Ebola exposure and appropriate precautions is provided.
For people who must travel to, or are in an Ebola outbreak area:
- Practice good hygiene.
- Use good hand washing techniques.
- Prevent contact with body fluids (e.g., a person showing symptoms, clothes, bedding, needles, medical equipment).
- Avoid contact with animals, including their blood, fluids, or raw meat.
Specific guidance is available from the U.S. Centers for Disease Control and Prevention (CDC) and the National Institute for Occupational Safety and Health (NIOSH) for certain occupations (e.g., healthcare, airline, emergency response, mortuary, laboratory, etc.).
What should I do if I have been to an affected area and I think I may be ill?
The Government of Canada states that you should call a health care provider immediately if:
- you are showing some of the above symptoms, and
- you or anyone in your household has recently travelled to an area where there is a confirmed Ebola virus outbreak.
Describe your symptoms and mention your recent travel over the phone before your appointment, so that health care staff can arrange to see you safely without potentially exposing themselves or others to the virus.
Although every effort is made to ensure the accuracy, currency and completeness of the information, CCOHS does not guarantee, warrant, represent or undertake that the information provided is correct, accurate or current. CCOHS is not liable for any loss, claim, or demand arising directly or indirectly from any use or reliance upon the information.