Ebola is a severe and often deadly disease caused by a virus. Symptoms include fever, diarrhea, vomiting, bleeding, and often, death.
Ebola can occur in humans and other primates (gorillas, monkeys, and chimpanzees).
The Ebola outbreak in West Africa, which has occurred since March 2014, is the largest in history. Almost 40% of the people who have gotten Ebola in this outbreak have died.
The virus poses a very low risk to people in the United States.
For the most up-to-date information, please visit the Centers for Disease Control and Prevention's (CDC) website: www.cdc.gov/vhf/ebola.
WHERE EBOLA OCCURS
Ebola was discovered in 1976 near the Ebola River in the Democratic Republic of the Congo. Since then, several small outbreaks have occurred in Africa. The 2014 outbreak is the largest. The countries most affected in this outbreak include:
- Sierra Leone
Ebola was previously reported in:
- United States
- United Kingdom
There are no current cases of Ebola in these countries. Most of these cases were due to people traveling from a country where Ebola was present.
There were four people diagnosed with Ebola in the United States. Two were imported cases, and two contracted the disease after caring for an Ebola patient in the United States. One man died from the disease. The other three recovered and are now free of Ebola.
HOW EBOLA CAN SPREAD
Ebola does not spread as easily as more common illnesses such as colds, the flu, or measles. There is NO evidence that the virus that causes Ebola is spread through the air or water. A person who has Ebola CANNOT spread the disease until symptoms appear.
Ebola can ONLY spread between humans by direct contact with infected body fluids including but not limited to urine, saliva, sweat, feces, vomit, breast milk, and semen. The virus can enter the body through a break in the skin or through mucous membranes, including the eyes, nose, and mouth.
Ebola can also spread by contact with ANY surfaces, objects, and materials that have been in contact with body fluids from a sick person, such as:
- Bedclothes and bedding
- Needles and syringes
- Medical equipment
In Africa, Ebola may also be spread by:
- Handling infected wild animals hunted for food (bushmeat)
- Contact with blood or body fluids of infected animals
- Contact with infected bats
Ebola does NOT spread through:
- Insects (mosquitoes)
Health care workers and people caring for sick relatives are most at risk for developing Ebola because they are more likely to come in to direct contact with body fluids.
The time between exposure and when symptoms occur (incubation period) is 2 to 21 days. On average, symptoms develop in 8 to 10 days.
Early symptoms of Ebola include:
- Fever greater than 101.5°F (38.6°C)
- Severe headache
- Sore throat
- Muscle pain
- Abdominal (stomach) pain
Late symptoms include:
- Bleeding from the mouth and rectum
- Bleeding from eyes, ears, and nose
- Organ failure
A person who does not have symptoms 21 days after being exposed to Ebola will not develop the disease.
There is no known cure for Ebola. Experimental treatments have been used, but none have been fully tested to see if they work well and are safe.
People with Ebola must be treated in a hospital. There, they can be isolated so the disease cannot spread. Health care providers will treat the symptoms of the disease.
Treatment for Ebola includes:
- Fluids given through a vein (IV)
- Blood pressure management
- Treatment for other infections
- Blood transfusions
Survival depends on how a person's immune system responds to the virus. A person also may be more likely to survive if they receive good medical care.
People who survive Ebola are immune from the virus for 10 years or more. They can no longer spread Ebola. It is not known whether they can be infected with a different species of Ebola. However, men who survive can carry the Ebola virus in their sperm for as long as 3 to 9 months. They should abstain from sex or use condoms for 12 months or until their semen has twice tested negative.
Long-term complications can include joint and vision problems.
When to Contact a Medical Professional
Call your health care provider if you have traveled to West Africa and:
- Know you have been exposed to Ebola
- You develop symptoms of the disorder, including fever
Getting treatment right away may improve the chances of survival.
There is currently no vaccine to protect against Ebola, although a vaccine is being tested.
If you plan to travel to one of the countries where Ebola is present, the CDC recommends taking the following steps to prevent illness:
- Practice careful hygiene. Wash your hands with soap and water or an alcohol-based hand sanitizer. Avoid contact with blood and body fluids.
- Avoid contact with people who have a fever, are vomiting, or appear ill.
- Do not handle items that may have come in contact with an infected person's blood or body fluids. This includes clothes, bedding, needles, and medical equipment.
- Avoid funeral or burial rituals that require handling the body of someone who has died from Ebola.
- Avoid contact with bats and nonhuman primates or blood, fluids, and raw meat prepared from these animals.
- Avoid hospitals in West Africa where Ebola patients are being treated. If you need medical care, the United States embassy or consulate is often able to provide advice about facilities.
- After you return, pay attention to your health for 21 days. Seek medical care right away if you develop symptoms of Ebola, such as a fever. Tell the health care providers that you have been to a country where Ebola is present.
Health care workers who may be exposed to people with Ebola should follow these steps:
- Wear protective clothing, including masks, gloves, gowns, and eye protection.
- Practice proper infection control and sterilization measures.
- Isolate patients with Ebola from other patients.
- Avoid direct contact with the bodies of people who have died from Ebola.
- Notify health officials if you have had direct contact with the blood or body fluids of a person who is sick with Ebola.
Ebola hemorrhagic fever; Ebola virus infection; Viral hemorrhagic fever; Ebola
Centers for Disease Control and Prevention. Ebola (Ebola Virus Disease). Updated January 13, 2016. Available at: www.cdc.gov/vhf/ebola. Accessed January 19, 2016.
Gostin LO, Lucey D, Phelan A. The Ebola Epidemic: A Global Health Emergency. JAMA. 2014;312(11):1095-6. PMID: 25111044 www.ncbi.nlm.nih.gov/pubmed/25111044.
World Health Organization. Ebola Virus Disease. Updated January 2016. Available at: www.who.int/csr/disease/ebola/en. Accessed January 19, 2016.
Review Date 10/10/2014
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team. Editorial update 01/22/2016.