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Definition: ebola from Philip's Encyclopedia

Virus that causes haemorrhagic fever. The ebola virus was first identified in humans during an outbreak in Congo in 1976. It is acquired through contact with contaminated body fluids. Death rates can be as high as 90%.


Summary Article: Ebola virus from The Columbia Encyclopedia

(ēbō'lə), a member of a family (Filovidae) of RNA viruses that cause hemorrhagic fevers. The virus, named for the region in Congo (Kinshasa) where it was first identified in 1976, emerged from the rain forest, where it survives in as yet unconfirmed hosts, possibly several species of fruit bats; experimental evidence also suggests that wild and domestic swine may be a reservoir of the disease. The virus can be fatal to chimpanzees and gorillas as well as humans. In 1989 a similar virus was found in monkeys imported to the United States.

Several strains of the virus found in Africa cause hemorrhagic fever; one found in the W Pacific does not. Once a person is infected with the virus, the disease has an incubation period of 2–21 days; however, some infected persons are asymptomatic. Initial symptoms are sudden malaise, headache, and muscle pain, progressing to high fever, vomiting, severe hemorrhaging (internally and out of the eyes and mouth) and in 50%–90% of patients, death, usually within days. The likelihood of death is governed by the virulence of the particular Ebola strain involved. Ebola virus is transmitted in body fluids and secretions; it may possibly also be transmitted through the air by aerosol droplets. There is no vaccine and no cure; a number of treatments for the disease, including a vaccine, are being developed, but they remain experimental.

Outbreaks of Ebola virus in humans have typically occurred in tropical rainforest regions in Central and West Africa. Among the countries affected have been Congo-Kinshasa (then Zaïre) and Sudan (in a region now in South Sudan), where outbreaks occurred in 1976 and 1979; since then other outbreaks have occurred in Gabon, Uganda, and both Congos. The largest and deadliest outbreak began in late 2013 in Guinea and spread to neighboring Liberia and Sierra Leone, with a few cases in some nearby African nations and in the United States and Europe; some 11,300 people—many more than in any prior outbreak—died in the following two years. Outbreaks have been exacerbated by underequipped and understaffed medical facilities, families caring for patients at home, suspicions that medical personnel are spreading the disease, and other factors.

  • See Quammen, D., Ebola (2014).
The Columbia Encyclopedia, © Columbia University Press 2017

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