Ebola

From ArticleWorld

Ebola (also known as Ebola Hemorrhagic Fever or EHF) is rare disease, with a high mortality rate. Ebola was discovered in 1976, seemingly carried and transmitted by fruit bats. Several epidemics have occurred, with mortality rate between 50% and 90%.

The Ebola virus

The Ebola virus is part of the Filoviridae family, and got its name from the river that was flowing close to the location where the first epidemic started. Several outbreaks have occurred ever since its discovery, with the most recent being in Etoumbi, Republic of Congo, in May 2005. The virus displays a filamentous structure, with approximately 80 nm in diameter, patching up in particles of various sizes, depending on the strain.

The Ebola virus has three strains:

• The Zaire ebolavirus is the first discovered strain. It is the most deadly of them all, with mortality rates recorded as high as 90%. It is the virus involved in the first outbreak in August 1976, with the first recorded case being that of Mabalo Lokela. His initial symptoms led the doctors to the diagnosis of malaria, but the symptoms became more and more serious until his death, 14 days later.

• The Sudan ebolavirus causes a less dangerous case of Ebola, but mortality rate is still as high as 53% in average.

• The Reston ebolavirus is a more recently discovered virus. It was identified in 1989, in a group of macaques. This strain is fatal in monkeys, but it doesn't cause illness in humans.

A fourth Ebolavirus-like strain was discovered in 1994, when a scientist developed acute medical condition after performing a necropsy on a wild chimpanzee. However, the researcher recovered from the disease, and little is known about this possible new strain.

Symptoms and treatments

The virus is transmitted by contact with infected fluids (eg blood) produced by the organism, and has an incubation period of 2 to 21 days.

Symptoms appear suddenly, involving high fever and headache, pain in muscles and joints, nausea and dizziness, making the disease more difficult to diagnose since these symptoms also occur in malaria or dysentery. Later, bleeding occurs, both internally and externally, associated with bloody stools, diarrhea, vomiting blood and low blood pressure.

Death occurs after 7 to 14 days from the occurrence of the symptoms, due to hypovolemic shock of organ failure.

Myths and facts

The Ebola virus got itself a serious reputation, but not all the facts that built it up are true. Ebola does not cause horrible symptoms, violent bleeding or liquefying organs. In fact, most of the bleeding is not even seen, because it occurs internally. When death occurs, the dead people look like any other people who died of hypovolemic shock or organ failure.

Most important of all, in spite of the common belief, the virus does have the time to spread after a person becomes infected. The incubation period can be as long as 3 weeks, and death doesn't occur two or three days after the virus infected the host.