[1] It started in early August 1967 when 30 people became ill in the West German towns of Marburg and Frankfurt and later two in Belgrade, Yugoslavia (now Serbia).

[2] In early August 1967, patients with unusual symptoms indicating an infectious disease were admitted to the university hospitals in Marburg and Frankfurt.

The first patients were treated in their homes for up to 10 days, even though the illness was described as beginning suddenly with extreme malaise, myalgia, headache, and a rapid increase in body temperature to as high as 39 °C (102.2 °F) or more.

[4] The incubation time of Marburg virus disease could only be estimated retrospectively, after the source of infection and the date of exposure were known.

All the patients at the three locations had contact with blood, organs, and cell cultures from African green monkeys (Cercopithecus aethiops).

The seven deaths out of the 31 initially diagnosed infections during the 1967 Marburg virus outbreak represent a case fatality rate of 23%.