He Helped Discover Ebola 50 Years Ago. He’s Still Worried.

In the fall of 1976, a plastic blue flask holding two glass vials arrived at the Institute of Tropical Medicine in Antwerp, Belgium.

One vial had broken en route, spilling its bloody contents into the half-melted ice in the container. The other still held blood from a Flemish nun who had died of a mysterious disease in Yambuku, Zaire, now the Democratic Republic of Congo. A small handwritten note accompanying the vials, the writing half bled into the icy water, read: “Fièvre jaune?” (“Yellow fever?”)

The task of identifying whether the woman had indeed died of yellow fever fell to the youngest member of the institute’s team, a 27-year-old Belgian scientist, Dr. Peter Piot.

He was far from the only one involved, though. Dr. Jean-Jacques Muyembe, a Congolese doctor who had trained in Belgium, had collected the samples and sent them to the lab. And several others in Antwerp and Yambuku had helped to isolate the virus from the sample and characterize the outbreak.

Exactly 50 years ago on Sunday, Dr. Piot and two others became the first people to get a look at the culprit: a large, spindly virus that would turn out to be among the most terrifying pathogens nature can produce.

The team named it Ebola, after a river near the center of the outbreak that had already killed the nun and dozens of others. Over the years, scientists would determine that Ebola has several forms, which together have killed tens of thousands of people. A current outbreak of the Bundibugyo species, also in Congo, has sickened nearly 9,000 people and claimed more than 4,200 lives as of Oct. 6.