"We heard a story about a hospital about 100 miles to the west. Some mysterious disease had gone through it a couple of years before. It killed all the doctors, all the nurses, all the patients. Everyone. The first time we heard it we said it was just a rumour. Then other local people told us the same story. I remember thinking, what the Hell could that have been?" - MSF field doctor, South Sudan

In 1976, in the north of what was then called Zaire, there was an outbreak of a new and deadly disease. It caused high fever, a rash, and bleeding from the internal organs. The disease moved for a while along the banks of the Ebola River, killing almost every person it struck. Then it disappeared again, as mysteriously as it had arrived.

The disease was named for the river where it had first struck and was eventually shown to be caused by a virus. A similar outbreak occurred about the same time in Southern Sudan, and then again in the same region some four years later. The next major outbreak was not until 1995, in the town of Kikwit in the south-west of the former Zaire.

The disease caused great fear, not only where it occurred but world-wide. This fear only abated once medical and epidemiological investigations showed how it was possible to manage an outbreak.