The ongoing Ebola outbreak in the Democratic Republic of Congo is now one year old and has killed more than 1,800 people.

The medic who came back from Congo has not shown symptoms of Ebola and will be under observation for up to two weeks.

The spread of Ebola from a rural area to Mbandaka, a city of more than 1 million people, has raised alarm as the deadly disease can spread more quickly in densely populated urban centers.