Ebola is shed through various bodily secretions, and transmission from human to human can occur in many ways. Infection can occur through contact with bodily fluids of other infected animals, and if proper barrier precautions are not taken, healthcare workers can even become infected from their own patients. There have been some documented cases of respiratory transmission, but those epidemics were swiftly dealt with and were never a problem.

The clinical symptoms of Ebola usually begin with a sudden onset of high fever, chills, myalgias and headache after an incubation period of around 5 to 10 days. The patient might also experience anorexia, nausea, vomiting, diarrhea, abdominal pain, pharyngitis, and an altered mental state. After about 5 to 7 days, a nonpruritic, maculopapular exanthematous rash can appear.

During the second week of the disease, severe hemorrhagic symptoms are manifested. Although gastrointestinal hemorrhaging is most common, bleeding can occur from any orifice, mucous membranes, and skin sites. Death is usually brought about by irreversible hemorrhagic shock and failure of all organs.