International ignorance of Ebola’s existence changed in 1976 when near simultaneous outbreaks occurred 500 miles apart in Nzara, Sudan and Yambuku, Zaire, killing a combined 431 people.[1] The existence of a (very poorly supplied)[2] Belgian mission hospital in Yambuku may have actually amplified the outbreak into an event that attracted international attention, as nosocomial cases (those originating in a medical setting) accounted for 234 of the 318 cases, and it was only after the surviving medical staff shut down the hospital that transmission slowed.[3] By the time an international medical team arrived in Yambuku, 95% of the cases had already occurred, and the local people had managed to contain the virus after the hospital’s closure through similar responses to the ones Hewlett would observe decades later in Gulu.[4] A large and active hospital in the town of Maridi near Nzara played a similar role in amplifying the outbreak in Sudan.[5]

Although they arrived at the tail end of active cases, researchers were eventually able to piece together partial details of the outbreaks. They determined that the two outbreak sites involved different strains of the virus—the strains subsequently named for each country—with Ebola getting its name from a river near Yambuku. They were also able to trace the 89% fatal Zaire ebolavirus outbreak in Yambuku back to a 44-year-old man who fell ill after he bought and ate monkey meat, and were able to link the 53% fatal Nzara case of Sudan ebolavirus back to a cotton factory where numerous bats were present.[6]

Despite the international medical community’s surveillance for filoviruses after the European Marburg outbreak from imported African monkeys in 1967 and the Central African Ebola outbreaks of 1976, the virus went silent. Only two isolated human incidents are known to have occurred between the initial ’76 outbreak and 1990s resurgence.[7] There is speculation amongst researchers that this might be because the virus—fortunately—never contaminated hospitals, as it had in 1976, during that fifteen-year respite.[8]

[1] WHO, “Ebola virus disease Fact Sheet,” April 2014. Online: http://www.who.int/mediacentre/factsheets/fs103/en/

[2] The Belgian hospital owned only five syringes, which were constantly reused and subsequently linked to 85 of the Yambuku cases: J.G. Breman et al., “The Epidemiology of Ebola Haemorrhagic Fever in Zaire, 1976,” in Ebola Virus Haemorrhagic Fever, Amsterdam: Elsevier/North-Holland Biomedical Press, 1978. Online: http://www.itg.be/internet/ebola/ebola-24.htm

[3] Barry S. Hewlett and Bonnie L. Hewlett, Ebola, Culture and Politics: The Anthropology of an Emerging Disease, Belmont, CA: Thomson Wadsworth, 2008; and Ibid.

[4] Barry S. Hewlett and Bonnie L. Hewlett, Ebola, Culture and Politics: The Anthropology of an Emerging Disease, Belmont, CA: Thomson Wadsworth, 2008.

[5] WHO/International Study Team, “Ebola haemorrhagic fever in Sudan, 1976,” Bulletin of the World Health Organization, 56(2): 1978. Online: http://whqlibdoc.who.int/bulletin/1978/Vol56-No2/bulletin_1978_56(2)_247-270.pdf

[6] Barry S. Hewlett and Bonnie L. Hewlett, Ebola, Culture and Politics: The Anthropology of an Emerging Disease, Belmont, CA: Thomson Wadsworth, 2008; and Xavier Pourrut et al., “The natural history of Ebola virus in Africa,” Microbes and Infection, 7(2005), 1005-1014.

[7] WHO, “Ebola virus disease Fact Sheet,” April 2014. Online: http://www.who.int/mediacentre/factsheets/fs103/en/

[8] C. J. Peters and J. W. LeDue, “An Introduction to Ebola: The Virus and the Disease,” The Journal of Infectious Diseases, 179, 1999. Online: http://jid.oxfordjournals.org/content/179/Supplement_1/ix.full.pdf

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