The Deadly Ebola Virus

Perhaps no virus strikes as much fear in people as Ebola, the cause of a deadly outbreak in the West African nation of Guinea.

The Guinea Ministry of Health has reported 127 cases of Ebola virus disease as of April 1, and 83 people had died, according to the World Health Organization. The cases of infected people include 14 health care workers, 8 of whom have died.

Ebola was first identified in 1976, when it appeared in outbreaks in Sudan and the Democratic Republic of the Congo. It is named for the Ebola River, which runs near the Congolese village where one of the first outbreaks happened.

Q. How deadly is Ebola?

A. The Ebola strain in the Guinea outbreak is the most lethal of the five known strains of the virus. It is called Ebola Zaire and kills up to 9 out of 10 infected people. But the high death rate might be due to a lack of modern medical care. It's hard to say exactly what the [death] rate would be in a modern hospital with all of its intensive care units.

Q. What are the symptoms?

A. At first, the symptoms are like a bad case of the flu: high fever, muscle aches, headache, sore throat, and weakness. They are followed quickly by vomiting, diarrhea, and internal and external bleeding, which can spread the virus. The kidneys and liver begin to fail.

Ebola Zaire kills people quickly, typically 7 to 14 days after symptoms appear.

A person can have the virus but not show any symptoms for as long as 3 weeks. People who survive can still have the virus in their system for weeks afterward.

Q. How does the virus spread?

A. Ebola isn't as contagious as more common viruses, such as colds, influenza, or measles. It spreads to people by close contact with skin and bodily fluids from infected animals, such as fruit bats and monkeys. Then it spreads from person to person the same way. It can also spread indirectly, such as by sharing a towel with an infected person.

The Guinea government has banned bat soup, which is a delicacy in that country, to help stop the spread. Clinicians don't know if that will help much, though, because the virus has already spilled over into humans. The key message is to minimize bodily fluid exposures.

Q. Is there a cure or a vaccine to protect against it?

A. No, but scientists are working on both. There is no specific treatment for Ebola. The only treatments available now are supportive kinds, such as IV fluids and, if available, medications to level out blood pressure, a respirator, and transfusions.

Q. Why do some people survive the virus?

A. That's hard to say. Clinical experts think several things might play a role, such as a person's age and genetic makeup, and whether they have other medical conditions. Those aren't proven factors, though.

Q. How can the outbreak be stopped?

A. Simple steps to control infection, such as gowns, gloves, and eye protection, will bring an end to it. Once basic hygiene is implemented, Clinicians and experts believe this Ebola outbreak will extinguish itself, as they all have in the past. Public health officials will have to wait a total of 6 weeks after the last case is reported before declaring the outbreak over.

Q. Could an Ebola outbreak happen in the United States?

Since the virus was first identified, all of the outbreaks in people have happened in Africa. It's possible that an infected person who appeared to be healthy could board a plane in Africa and fly to the U.S. But it's not something that we've ever seen before. The outbreaks generally have happened in poor, isolated communities, so those infected didn't have the resources to travel far.

One of the five Ebola virus strains caused an outbreak in laboratory monkeys in Reston, VA, outside Washington, DC. People who were exposed to that strain of Ebola virus did not get sick. But they developed antibodies to it. There have been no reports of Ebola illnesses or death in people in the U.S.

SOURCES: Amesh Adalja, MD, associate, Center for Biosecurity, University of Pittsburgh Medical Center.World Health Organization.