The Ebola virus is an enveloped virus that causes Ebola Virus Disease (EVD). First appearing in 1976, outbreaks thus far have occurred only in Africa. The manner in which the virus appears is not firmly established, however, best evidence to date suggests that the virus lives in fruit bats. Contact with an infected animal (a bite or contact with bodily secretions or organs) causes the initial transmission from animals to people. Human to human transmission can occur through direct contact with the blood or body fluids of an infected person, or direct contact with objects that have been contaminated with infected secretions. The virus enters the body through broken skin or mucous membranes.
EVD is not believed to be transmitted by air, water, or cooked food. Consumption of raw milk, raw meat, or raw organs of an infected animal is believed to be a potential source of infection for people. All food (especially meat) should be thoroughly cooked to prevent any risk of transmission. Previous EVD outbreaks have spread to the family and friends and healthcare workers of the infected people. Transmission is believed to occur through close contact with infection secretions while caring for a sick person or handling of the body after death, causing similar exposure to infected bodily fluids.
Human to human transmission is believed to occur through:
- Contact with blood or secretions of an infected person (direct contact) either while an infected person is alive, or after death
- Exposure to contaminated needles, bandages, clothing or other infected objects (indirect contact) in the environment
While an infected person must have symptoms of EVD to be contagious, people who recover from EVD can still transmit the Ebola virus for an unknown period of time through body fluids after symptoms have stopped. Persons are considered infectious as long as their blood or body fluids contains the virus, which can be up to 8 weeks based on limited evidence from past outbreaks.