According to the Center for Disease Control and Prevention (CDC) there are various symptoms people exposed to the Ebola virus may exhibit. These include:
| Symptom | % of Frequency |
| Fever (greater than 38.6°C or 101.5°F) | ≥90 |
| Weakness | 80-90 |
| Diarrhea | 80-90 |
| Vomiting and Nausea | 70-80 |
| Abdominal (stomach) pain | 50-60 |
| Headache | 50-60 |
| Sore throat | 50-60 |
| Unexplained bruising or bleeding | 40-50 |
Symptoms typically appear between 2 and 21 days after exposure, however the average is 8 to 10 days. A patient must have these symptoms to be able to spread the disease. If after 21 days after exposure to the Ebola virus a person has not developed these symptoms they will not develop the disease.
Table adapted from data presented in: Fauci, A.S. (2014). "Ebola -- understanding the global disparities in health care resouces." New England Journal of Medicine, 371: 1084-1086. doi: 10.1056/NEJMp1409494
From the CDC:
Because the natural reservoir host of Ebola viruses has not yet been identified, the way in which the virus first appears in a human at the start of an outbreak is unknown. However, scientists believe that the first patient becomes infected through contact with an infected animal, such as a fruit bat or primate (apes and monkeys), which is called a spillover event. Person-to-person transmission follows and can lead to large numbers of affected people. In some past Ebola outbreaks, primates were also affected by Ebola and multiple spillover events occurred when people touched or ate infected primates.
When an infection occurs in humans, the virus can be spread to others through direct contact (through broken skin or mucous membranes in, for example, the eyes, nose, or mouth) with
Ebola is not spread through the air, by water, or in general, by food. However, in Africa, Ebola may be spread as a result of handling bushmeat (wild animals hunted for food) and contact with infected bats. There is no evidence that mosquitoes or other insects can transmit Ebola virus. Only a few species of mammals (e.g., humans, bats, monkeys, and apes) have shown the ability to become infected with and spread Ebola virus.
Healthcare providers caring for Ebola patients and family and friends in close contact with Ebola patients are at the highest risk of getting sick because they may come in contact with infected blood or body fluids.
During outbreaks of Ebola, the disease can spread quickly within healthcare settings (such as a clinic or hospital). Exposure to Ebola can occur in healthcare settings where hospital staff are not wearing appropriate personal protective equipment.
Dedicated medical equipment (preferably disposable, when possible) should be used by healthcare personnel providing patient care. Proper cleaning and disposal of instruments, such as needles and syringes, also are important. If instruments are not disposable, they must be sterilized before being used again. Without adequate sterilization of instruments, virus transmission can continue and amplify an outbreak.
Once people recover from Ebola, they can no longer spread the virus to people in the community.