Ebola is a disease caused by a hemorrhagic fever virus. Fatality rates have varied from 25% to 90% in past outbreaks. The average fatality rate is around 50%.

What is Ebola?

Ebola is a virus that causes severe inflammation and tissue damage throughout the body. It is known as a hemorrhagic fever virus, because it can cause problems with the clotting system of the body and lead to internal bleeding, as blood leaks from small blood vessels. Six different species of the virus have been found, but only four are known to cause disease in humans.

Ebola is spread through direct contact with body fluids ― blood, saliva, sweat, tears, mucus, vomit, feces, breast milk, urine and semen ― of people infected with it. It is also spread by touching things that have been contaminated with these fluids.

How is the Ebola virus transmitted?

The Ebola virus is not believed to be spread through the air, unless the patient is undergoing medical procedures that can release respiratory droplets into the air, such as having a breathing tube inserted or removed or undergoing bronchoscopy.

Experts believe that people only become infectious once they start to have symptoms. The risk of being infectious in the early course of Ebola is generally low and appears to become much higher in the later stages of the disease.

Who is at risk for Ebola?

If you have been to a place where people have been sick with Ebola or if you have been exposed to animals that carry the virus, you may be at risk for infection, especially if you:

• Were in a place where people with Ebola were being treated and had contact with them.
• Touched blood or body fluids (saliva, sweat, tears, mucus, vomit, feces, breast milk, urine or semen) from a person infected with Ebola.
• Touched sheets, towels, clothes, personal objects or other items that had contact with a person infected with Ebola.

How can Ebola be prevented?

Since Ebola can be serious, prevention is essential. If you travel, be aware of CDC updates on Ebola outbreaks.

Ebola Vaccine

A vaccine for Ebola was approved by the Food and Drug Administration in December 2019. It is a one-dose shot that protects against the variant of the Ebola virus that has caused the most serious outbreak so far. This vaccine is not likely to be effective against the Ebola Sudan strain that caused a 2022 outbreak in Uganda.

The CDC’s Ebola vaccine recommendations urge adults age 18 and older to receive the Ebola vaccine if they are at risk for exposure to the virus. This includes researchers who work with the virus in laboratories. It also includes health care workers, first responders and others at risk of exposure to the Ebola virus, whether they work at designated Ebola-ready treatment centers in the U.S. (including the biocontainment unit at The Johns Hopkins Hospital) or care for patients in other countries.

Other Ebola Outbreak Safety Precautions

If you travel to affected countries or think you have been exposed to someone suspected or confirmed to have Ebola, follow the Centers for Disease Control and Prevention’s guidance for protecting yourself. In addition:

• Follow all instructions you are given if you are in an area where Ebola infections are occurring.
• Wash your hands often, using soap and water. Or use an alcohol-based hand sanitizer often.
• Don’t touch your eyes, nose or mouth with your hands. If you must, make sure to wash your hands first. 
• Cover any cuts, scrapes or other wounds you have.
• Don’t touch body fluids from a person with Ebola.
• Don’t touch sheets, clothes, towels, medical supplies or personal items of a person with Ebola.

What to Do If You Are Exposed to the Ebola Virus

If you have been exposed to Ebola:

• Call your health care provider, who can talk with local health staff to see what action may be needed.
• Keep watch for early symptoms of Ebola for 21 days.
• Take your temperature every morning and evening to check for fever.

If you have a fever or other Ebola symptoms:

• Don’t panic. Keep in mind that other illnesses can cause similar symptoms.
• Call the nearest hospital emergency room. Explain that you have been exposed to Ebola and have symptoms. Do this before going to the hospital. This will help the hospital staff get ready for your arrival.
• Keep in mind that hospital staff members may wear protective equipment, such as masks, gowns, gloves and eye protection. This is to prevent the possible virus from spreading.
• Follow all instructions the hospital staff gives you.

Ebola Symptoms

Symptoms of Ebola can start two to 21 days after being infected by the virus. They most often start about eight to 10 days after being exposed to the virus.

Early symptoms are similar to those of the flu, and may include:

• Fever
• Chills
• Weakness
• Severe headache
• Muscle aches

These symptoms may show up several days later:

• Confusion
• Chest pain
• Trouble breathing
• Nausea and vomiting
• Diarrhea
• Stomach pain
• Less urine or no urine
• Unusual bleeding or bruising
• A red rash that doesn’t itch or hurt, and may peel after a while
• Redness and bleeding from the eyes, nose, mouth and rectum

Later stages of the illness can cause:

• Organ failure
• Inflammation of the brain
• Seizures
• Lack of blood flow in the body (shock)
• Death

Ebola Diagnosis

Diagnosis of Ebola starts with health practitioners asking you about your medical history and when you may have been exposed to Ebola. They may ask about your recent travel and contact with sick people. 

You will have tests to check for the cause of your symptoms. The symptoms of Ebola can also be caused by other viruses and bacteria. To rule out other diseases and conditions, you may have tests such as:

• Blood tests. Blood is taken from a vein in your arm or hand. This is done to check for certain chemicals that can show if you have an Ebola infection or other illness. Blood tests also check for problems with your blood, kidneys, liver and other organs.
• Oral swab. A stick with a small piece of cotton at the tip is wiped inside your mouth. This is done to check for viruses and bacteria in your saliva.
• Urine test. A sample is collected when you urinate. This is done to look for bacteria that may be causing your symptoms.
• Stool culture. A small sample of stool is collected from your rectum or from a bowel movement. The sample is checked for viruses and bacteria.
• Sputum culture. A small sample of mucus coughed from the lungs is collected. It is checked for viruses and bacteria.

Ebola Treatment

Ebola is hard to treat, but there are some therapies available for certain strains of the virus. For example, there are two FDA-approved monoclonal antibody treatments for the Ebola Zaire strain.

Treatment for Ebola also involves supportive care, which means helping your body with therapies for severe illness while it fights the disease.

Supportive care may include:

• Fluids given through a vein (IV) to help keep your body hydrated
• Supplemental oxygen or assisted ventilation to keep enough oxygen in your body
• Dialysis to help clear waste from the blood
• Vasopressor drugs to help raise blood pressure that is too low
• Medications to help your blood clot 

Blood, urine and other tests may be done regularly. This is to check for chemicals that show how well the organs are working. The tests also look for signs of the virus that continue or go away. Your blood pressure will be checked regularly.

In rare cases, experimental treatment may be used. These are treatments that are not yet proven or approved by the FDA but may work and may be allowed in some cases.

Experimental treatments may include:

• Convalescent serum. The liquid part of blood (serum) is taken from a person who is recovering from Ebola, and it is put into the body of a person sick with Ebola.
• Medications. This includes medicines such as monoclonal antibodies that try to stop the virus from reproducing in the body. There are currently two monoclonal antibodies that are FDA approved to treat the Ebola Zaire strain, but more are being developed for other strains of the virus, including the Ebola Sudan strain.

If treatment is ineffective or unavailable, Ebola may cause death in an average of about 10 days from the start of symptoms.

Ebola Virus Recovery

• After recovering from Ebola, you may have body aches and weakness for weeks or months.
• Ebola can last in semen for at least three months after recovery. A man should use a condom or not have sex.
• Women should not breastfeed until talking with their doctor. 
• A person who has recovered from Ebola may be immune for 10 years or longer. It is not known if this includes immunity to all species of the virus.