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9 of the worst viruses on Earth

By: Mary Jo DiLonardo on June 6, 2018, 10:03 a.m.
ebola virus

Photo: CDC

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Ebola virus disease

The first known cases of Ebola, also known as Ebola hemorrhagic fever, were in 1976. Although early outbreaks occurred in remote villages in Central Africa near tropical rain forests, reports the WHO, more recent outbreaks were in urban areas as well. This severe illness results from a virus that is transmitted to people from wild animals then spread from humans to humans. The average fatality rate is 50 percent but has been as high as 90 percent in some outbreaks.

There are no Ebola vaccines but there are clinical trials under evaluation. Symptoms range from fever and vomiting to bleeding and weakness. Recovery depends on good supportive care and the patient's immune system.