Ebola - Today's News, Tomorrow's Lesson

PBS NewsHour Extra

Four African nations are fighting to contain the largest outbreak in history of Ebola, a virus with no official vaccine or treatment.

About 1,600 people have contracted Ebola in Sierra Leone, Liberia, Nigeria and Guinea since the outbreak began in February. More than 880 have died from the virus.

International aid workers from the Red Cross and other organizations have traveled to the affected areas to treat and contain the disease.

Two Americans have been infected with the virus: aid worker Dr. Kent Brantly and Christian missionary Nancy Writebol. Both have arrived at Emory University Hospital in Atlanta to receive an experimental treatment for the virus.

Ebola is a virus that appeared in Sudan and the Democratic Republic of Congo in 1976, according to the World Health Organization. It spreads in human populations through direct contact with the bodily fluids of an infected person.

Early symptoms of Ebola include fever and a sore throat. As it progresses, the virus can cause kidney and liver malfunction as well as internal and external bleeding.

The current outbreak was difficult to trace at the onset, according to Dr. Estrella Lasry, a physician with Doctors Without Borders. Experts believe it began in the forest region in Gueckedou in Guinea, later spreading to both rural and urban areas.

It is challenging to contain Ebola because its early symptoms are similar to many other viruses, making it hard to identify at the onset. People can also contract the virus while performing funeral rites for victims of the virus.

There is a relatively small risk of a large outbreak occurring in the U.S., according to health officials. Airports across the U.S. are on the lookout for travelers who show symptoms of the virus.