Ebola was a highly contagious disease that caused its victims to bleed to death. It was caused by a virus.
In 1989, there was an Ebola virus outbreak in Tanganyika, a country in Africa. (AUDIO: The Sentinels of the New Dawn)
In 2008, when the Cardiff time rift was leaking, Owen Harper was worried someone with Ebola might come through. (TV: End of Days)
In 2014, the Sentinels of the New Dawn intended to cause an Ebola epidemic to take power. (AUDIO: The Sentinels of the New Dawn)