Africa

Ebola viral disease is a highly infectious illness with fatality rates up to 90 percent, according to the U.N. World Health Organization. Symptoms initially include a sudden fever as well as joint and muscle aches and then typically progress to vomiting, diarrhea and, in some cases, internal and external bleeding — you can see a full, grim description of symptoms compiled by the Centers for Disease Control and Prevention (CDC) here.

The virus spreads through contact with bodily fluids of someone who is infected. Reports of human infections usually first emerge in remote areas that are in proximity to tropical rain forests, where humans can come into contact with animals such as chimpanzees, gorillas and forest antelope. The consumption of bush meat is often a precursor to such outbreaks. The WHO says fruit bats are probably the natural host for the virus.