14 October 1974
Marburg Disease, also known as green Monkey disease is a variant of HemorrhagicFever that was first identified in green monkeys. It gets its namefrom the city of Marburg, Germany, where it caused small epidemics. In 1974, the virus killed more than three hundred people in Northern Zaire (Now Democratic Republic of the Congo) and Sudan. On 14 October 1974 Scientist finally identified the virus that had been causing the deaths to be the Marburg Virus.
References

Who Marburg haemorrhagic fever [online] Available at: www.who.int [Accessed on 20 September 2013]|

News-Medical What is Marburg Virus? [Online] Available at: www.news-medical.net [Accessed on 20 September 2013]