This post is the second part in a short series I’m writing on the history of Ebola. For immediate information about how to help prevent the further spread of Ebola and keep yourself safe please consult and share the Ebola Facts website.
While there are numerous virology and pathology articles trying to pin down the scientific facts of the elusive Ebola virus, social scientists do not seem to have thoroughly studied the dreaded virus…and it’s not hard to imagine why historians and anthropologists would shy away from field research on a disease like Ebola.
I haven’t researched Ebola in the field, and when reading this historical summary please note that I am not a doctor, nor am I a historian of science, so please consult the sources cited for more thorough information. That being said, as compellingly argued in a recent Journal of African History article on the social history and biology of HIV/AIDS in Africa, scientific understanding and treatment is often enhanced by a greater awareness of the social and cultural contexts in which diseases have developed and spread. These kind of historical insights are why I hope I’m able to offer something by giving an account of Ebola from an African history perspective without having an advanced background in biology.
However a quick synopsis of Ebola’s basic biology is of course necessary. Ebola virus disease (EVB) or Ebola hemorrhagic fever (EHF) is an RNA virus that is part of the Filoviridae Family of diseases of which there are three members—Marburg Virus, Cueva Virus, and, our concern, Ebola Virus. Within its branch of the Filoviridae tree, Ebola comes in five species: Zaire ebolavirus (EBOV, discovered in1976), Sudan ebolavirus (SUDV, 1976), Tai Forest ebolavirus (TAFV, 1994), Reston ebolavirus (RESTV, 1989), and Bundibugyo ebolavirus (BDBV, 2007). Amongst these five strains, Zaire, Sudan, and Bundibugyo are responsible for the deadly outbreaks in Africa, while Reston has never caused human illness or death despite several people testing positive for it (they remain asymptomatic), and there has been only one human known case of Tai and the victim fully recovered within six weeks.[1]
Ebola is a public health nightmare because it can be contracted easily and is almost always fatal. Ebola is introduced into human populations from contact with the highly contagious blood or body fluids of infected animals such as monkeys or bats, and then spreads through human-to-human transmission. There is also some inconclusive evidence that the virus can spread through airborne nasal and throat secretions.[2] The signs and symptoms of Ebola have been well publicized, and they include the sudden onset of fever, sore throat, extreme weakness, headache, and muscle pain within 2 to 21 days of infection. Additional symptoms soon appear that make transmission more likely, including vomiting, diarrhea, rashes, both internal (gastrointestinal) and external (gums, nose) bleeding.[3] There is no known treatment for Ebola (although vaccines are in the works), and once the onset of symptoms occur, victims usually die within 5 days with Zaire ebolavirus’s fatality rate nearing 90% and Sudan’s being slightly less between 53% and 66%.[4]
Bats on an island in Lake Kivu (Mark Duerksen 2014)
One of the greatest mysteries surrounding Ebola has been identifying the “reservoir”—the animal that asymptomatically carries the virus between outbreaks, allowing it to go silent for years at a time. Scientists have come to consider fruit bats as the most likely reservoir candidates after capturing and testing thousands of African animals, and after numerous attempts to infect various animals and plants, which confirmed fruit bats could contract and carry the virus.[5] However most human cases are thought to be the result of exposure (hunting, eating) to infected nonhuman primates and duikers (small deer) that have acquired the virus from bats.[6]
[1] WHO, “Ebola virus disease Fact Sheet,” April 2014. Online: http://www.who.int/mediacentre/factsheets/fs103/en/
[2] C. J. Peters and J. W. LeDue, “An Introduction to Ebola: The Virus and the Disease,” The Journal of Infectious Diseases, 179 (1999), ix-xvi. Online: http://jid.oxfordjournals.org/content/179/Supplement_1/ix.full.pdf
[3] WHO, “Ebola virus disease Fact Sheet,” April 2014. Online: http://www.who.int/mediacentre/factsheets/fs103/en/
[4] A. S. Carroll et al., “Molecular Evolution of Viruses of the Family Filoviridae Based on 97 Whole-Genome Sequences,” Journal of Virology, 87(2013), 2608-2616. Online: http://www.ncbi.nlm.nih.gov/pubmed/23255795
[5] Ibid; and Xavier Pourrut et al., “The natural history of Ebola virus in Africa,” Microbes and Infection, 7(2005), 1005-1014. Online:
[6] A. S. Carroll et al., “Molecular Evolution of Viruses of the Family Filoviridae Based on 97 Whole-Genome Sequences,” Journal of Virology, 87(2013), 2608-2616. Online: http://www.ncbi.nlm.nih.gov/pubmed/23255795
Arcade Africa 