In Brief:
Ebola is an extremely serious hemorrhagic fever caused by an African filovirus. There are actually five known ebolaviruses today, with the original virus being discovered in and named after the Ebola River valley in the Congo (at the time, Zaire, hence its name, Ebola Zaire). The deadliest is the Zaire ebola virus, which kills from 80%-90% of its victims. Zaire virus outbreaks occur more frequently than outbreaks of other forms of Ebola, and have been happening off and on since 1976. However, regardless of their cause, many of the symptoms associated with Ebola are extremely serious, so if you experience them, you should report them to your doctor promptly.
