What Is Ebola? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Ebola virus disease, or Ebola for short, is a contagious illness that is native to Africa. It belongs to a family of viruses known as filoviruses (Filoviridae). These viruses cause hemorrhagic fever — a serious condition that can lead to severe bleeding, organ failure, and death.

Humans contract Ebola from infected animals. After the initial transmission, the virus can be passed on through contact with body fluids.

Since Ebola was discovered in 1976, several outbreaks have occurred, primarily in Africa.

The most severe outbreak happened between 2014 and 2016, causing more than 11,000 deaths, mostly in three countries in West Africa. The virus has flared on and off since then, including the second-deadliest outbreak in 2018 in Democratic Republic of the Congo, with more than 2,000 deaths. In 2022, smaller outbreaks have been reported in Democratic Republic of the Congo and Uganda, according to the U.S. Centers for Disease Control and Prevention (CDC).

On average, only about one-half of the people who contract Ebola will survive, according to the World Health Organization (WHO).

A vaccine for Ebola was approved by the U.S. Food and Drug Administration (FDA) in December 2019,

 and the first treatment for the virus was approved in October 2020.

Ebola Strains

Researchers have identified the following five strains of the Ebola virus:

  • Tai Forest (formerly called Ivory Coast)
  • Sudan
  • Zaire (the former country name of Democratic Republic of the Congo)
  • Bundibugyo
  • Reston

The virus that caused the 2014–2016 outbreak in Africa belonged to the Zaire species.

Reston is the only strain that doesn’t cause severe disease in humans.

Another type of Ebola virus, called Bombali, was recently discovered in bats, but it’s not known if it causes disease in other animals or people.

Signs and Symptoms of Ebola

Symptoms of Ebola usually crop up between 8 and 10 days after infection.

But they can begin anywhere from 2 to 21 days after contact with the virus.

Early symptoms might include:

  • Fever
  • Severe headache
  • Chills
  • Joint and muscle aches
  • Weakness or fatigue

These first signs may be vague and hard to recognize as Ebola.

As time goes on, symptoms may become more severe and include:

  • Nausea, vomiting, diarrhea, or stomach pain
  • Red eyes
  • Chest pain
  • Cough or sore throat
  • A raised rash
  • Severe weight loss
  • Bruising
  • Bleeding (usually from the eyes)
  • Internal bleeding

Learn More About Signs and Symptoms of Ebola

Causes and Risk Factors of Ebola

Scientists don’t know exactly where the Ebola virus comes from, but they believe fruit bats are the most likely hosts.

Bats carrying the virus may transfer it to other animals (such as apes and monkeys). Human beings can contract Ebola through close contact with an infected animal.

When humans pick up Ebola, they can spread the virus through their bodily fluids and secretions, such as blood, vomit, and feces, and any materials contaminated with those fluids.

You may contract Ebola through sexual contact or needle-sharing, as well. Some research has found men who have recovered from Ebola may spread the virus through their semen for several months following their recovery, according to the CDC.

Healthcare workers who treat Ebola can be infected if they come in close contact with patients.

People with Ebola remain contagious for as long as their blood and body fluids contain the virus. In some cases, contact with a deceased body of someone who had Ebola can transmit the virus.

Ebola and Animals

Close contact with infected bats or other animals with the virus is one way to contract Ebola from animals. Another is handling or eating bushmeat — wild animals hunted for food — in areas where Ebola is common.

Some studies have shown that Ebola has been detected in dogs and cats that live in affected areas.

While there are no reports of dogs or cats spreading the virus to people or other animals, some unusual pets, such as exotic monkeys, apes, or pigs, may spread Ebola if they’re infected with it, per the CDC.

There’s no evidence that the Ebola virus can be spread through insect bites.

Risk Factors

You may be more at risk for contracting Ebola if you:

  • Travel to areas in Africa where outbreaks have occurred
  • Treat or care for other people with the virus
  • Conduct research on high-risk animals
  • Prepare the bodies of people who have died from Ebola for burial
Your risk of being infected with Ebola is very low, unless you travel to places where the virus is prevalent and have had close contact with other people or animals who have the virus.

How Is Ebola Diagnosed?

Diagnosing Ebola can be tricky. Some of the symptoms mimic those of other illnesses, such as malaria and typhoid fever.

According to the CDC, the criteria for determining if a person has Ebola early on includes both of the following:

  • A combination of symptoms suggestive of the virus
  • A possible exposure to Ebola within 21 days of when symptoms started

If someone does show early signs of the virus and has a possible exposure, public health authorities should be notified. Additionally, the patient should be isolated and given a blood test.

Ebola can be detected in a person’s blood, but it may take up to three days after symptoms begin for the virus to reach measurable levels. A positive blood test indicates that Ebola was identified and confirmed.

Some blood tests that are used to detect Ebola are:

  • Enzyme-linked immunosorbent assay (ELISA)
  • Reverse transcriptase polymerase chain reaction (PCR)

Prognosis of Ebola

According to the WHO, the average Ebola case death rate is around 50 percent. But fatality rates have ranged from 25 to 90 percent, depending on the outbreak and virus strain.

Scientists aren’t sure why some people are able to bounce back from Ebola, while others aren’t. Receiving prompt supportive treatment is one way to improve your chances of surviving the virus.

Researchers have not yet been able to determine the effectiveness of the newly approved treatments for Ebola, but there have been some hopeful signs, with two early trials stopped quickly and rolled out live in 2019 because they demonstrated a clear ability to significantly reduce the fatality rate from the virus. And the government of Uganda moved quickly in the fall of 2022 to launch clinical studies of the vaccine’s impact on the new outbreak there.

Duration of Ebola

Recovery is typically very slow for people who do survive Ebola. It can take months to regain strength, and the virus can remain active in the body for a while.

Studies show survivors of Ebola have antibodies that can be detected in their blood up to 10 years after they’ve recovered from the virus.

Treatment and Medication Options for Ebola

On October 14, 2020, the FDA approved an official treatment for the Ebola virus.

 The approval of Inmazeb, a combination of three types of monoclonal antibodies, comes just shy of a year after the FDA approved an Ebola vaccine, in December 2019.

Developed by the pharmaceutical company Regeneron, Inmazeb is made up of atoltivimab, maftivimab, and odesivimab-ebgn — man-made antibodies that imitate those released by the body’s immune system. It works by targeting and attaching itself to a glycoprotein on the surface of the virus and then blocking the virus from entering cells.

Inmazeb was tested in a clinical trial during the 2018–2019 Ebola outbreak in the Congo. Roughly 38 percent of study participants who received the treatment died compared with the 51 percent who died taking a control treatment. Inmazeb is delivered intravenously, and now with FDA approval, doctors treating those infected with Ebola should have much easier access to the drug.

Supportive Care

Typically, people with Ebola will be given supportive care, which includes:

  • Receiving extra fluids and oxygen
  • Maintaining blood pressure
  • Replacing lost blood
  • Treating other infections
Supportive care that’s started early can significantly improve a person’s chances of survival.

Medication Options

Scientists are studying several novel treatments for Ebola, which include blood transfusions from survivors and mechanical filtering of blood from patients.

Another experimental therapy, called ZMapp, combines three monoclonal antibodies that bind to the protein of the Ebola virus, inactivating it.

In the 2014 Ebola outbreak, two Americans were treated with the drug ZMapp and both survived, although it’s not known what role the drug played in their survival or recovery. Also, some patients with Ebola who were given ZMapp died.

Studies to determine whether the medicine is an effective option for Ebola are still in progress.

Ebola Vaccines

The first official Ebola vaccine was approved by the FDA on December 19, 2019. Ervebo, a vaccine developed by the pharmaceutical company Merck, was shown to effectively protect people from getting infected during a trial that took place during the 2014–2016 Ebola outbreak in West Africa.

The vaccine is approved for adults age 18 and older, and was tested on roughly 15,000 people in Africa, Europe, and North America. Given as a single-dose injection, the vaccine may cause side effects including pain, headache, fever, fatigue, joint and muscle aches, and redness or swelling at the injection site.

Alternative and Complementary Therapies

Because treatment options aren’t always effective for Ebola, some people look to alternative approaches. Most of these methods have not been proven to work and are merely internet claims that you should not rely on if you are ill with Ebola.

Prevention of Ebola

Measures that may prevent the spread of Ebola include the following:

  • Avoid visiting areas with known outbreaks.
  • Isolate infected patients from anyone who doesn’t have Ebola.
  • Have healthcare workers wear protective gear, including gloves, masks, goggles, gowns, and other clothing, while caring for Ebola patients.
  • Decontaminate or destroy any surfaces or materials a patient has had contact with, including syringes, needles, and other medical equipment.
  • Wash hands frequently with soap and water or use an alcohol-based sanitizer.
  • Avoid handling or eating bushmeat.
  • Monitor anyone who comes into contact with an Ebola patient.

The Ebola virus can survive for several hours on dry surfaces, like doorknobs and countertops. And it can live for up to several days at room temperature in body fluids.

The virus can be killed using a U.S. Environmental Protection Agency (EPA)–registered hospital disinfectant with a label for a “nonenveloped virus.”

Controlling Outbreaks

Since the first case of Ebola, various outbreaks have occurred. Once the virus spreads to people, it can quickly transmit throughout families, healthcare settings, and other public areas.

Spotting cases of Ebola early on may be the key to stopping outbreaks.

“Contact tracing” is one tactic that experts use to identify people who have been exposed to someone with Ebola. It involves tracking down everyone who has come in direct contact with the sick person.

These contacts are watched for signs of Ebola for 21 days from the last day they were around the infected patient. If a contact develops a fever or other classic symptoms of Ebola, they will be immediately isolated and tested for the virus.

The WHO considers an Ebola outbreak to be over after 42 days (or two incubation periods) have passed without any new infections, according to the CDC.

Learn More About Ebola Outbreaks

Complications of Ebola

Ebola can cause serious complications, such as:

  • Organ failure
  • Severe bleeding
  • Jaundice
  • Seizures
  • Coma
  • Delirium
  • In many cases, the virus is harmful enough to cause death

Research and Statistics: Who Has Ebola?

During the 2014–2016 outbreak in West Africa — the worst on record — the CDC says there were a total of 28,616 Ebola cases and 11,210 deaths reported in Guinea, Liberia, and Sierra Leone. An additional 36 cases and 15 deaths occurred outside of these three countries.

Ebola isn’t currently considered a threat for people who don’t live in sub-Saharan Africa.

In the 2014-2016 outbreak, 11 people with Ebola were treated in the United States, nine of whom contracted the virus in western Africa. Two of these patients died.

Black Communities and Ebola

Ebola primarily affects people in sub-Saharan Africa, which has a predominantly Black population. But anyone can become infected with the virus.

Some experts have argued that labeling Ebola as a virus that impacts Black people can fuel racism. They say people should know that the location where you live is a risk factor for Ebola, not your race or ethnicity, according to a BBC report.

Related Conditions and Causes of Ebola

Some medical diseases share many of the signs and symptoms of Ebola. Conditions that may be closely related to Ebola include:

  • Marburg virus

  • Malaria
  • Typhoid fever

Editorial Sources and Fact-Checking

Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

Sources

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