What is Ebola?

The Ebola virus is a rare and deadly disease most commonly affecting people and nonhuman primates (monkeys, gorillas, and chimpanzees). It is caused by an infection with a group of viruses. 
According to the Centers for Disease Control and Prevention, scientists conclude that people are initially infected with Ebola virus through contact with an infected animal, such as a fruit bat or nonhuman primate. This is called a spillover event. Afterward, the virus spreads from person to person, potentially affecting a significant number of people.

Transmission

The Ebola virus spreads through direct contact (broken skin or mucous membranes in the eyes, nose or mouth) with:

  • Blood or body fluids (urine, saliva, sweat, feces, vomit, breast milk and semen) of a person who is sick with or has died from Ebola;
  • Objects (needles and syringes) contaminated with body fluids from a person sick with Ebola or the body of a person who died from Ebola;
  • Infected fruit bats or nonhuman primates (apes and monkeys);
  • Semen from a man who recovered from Ebola (through oral, vaginal or anal sex).

The Ebola virus CANNOT spread to others when a person shows no signs or symptoms of Ebola virus disease. Additionally, Ebola virus is not usually transmitted by food. However, in certain parts of the world, Ebola virus may spread through the handling and consumption of bushmeat (wild animals hunted for food). There is also no evidence that mosquitoes or other insects can transmit Ebola virus.

Ebola Signs and Symptoms

Symptoms of Ebola Virus Disease (EVD) include:

  • Fever
  • Severe headache
  • Muscle pain
  • Weakness
  • Fatigue
  • Diarrhea
  • Vomiting
  • Abdominal pain (stomach pain)
  • Unexplained hemorrhage (bleeding or bruising)

Symptoms may appear anywhere from two to 21 days after contact with the virus, with an average of eight to ten days. Many common illnesses can have these same symptoms, including influenza (flu) or malaria.

Ebola (or Ebola Virus Disease, EVD) is a rare but severe and often deadly disease. Recovery from EVD depends on good supportive clinical care and the patient’s immune response. Studies show that survivors of Ebola virus infection have antibodies (molecules that are made by the immune system to label invading pathogens for destruction) that can be detected in the blood up to ten years after recovery.

Where is it most common?

The Ebola virus first appeared in 1976 near the Ebola River in what is now the Democratic Republic of Congo. Since then, the virus has emerged periodically and infected people in several African countries. All but two cases in the United States have originated overseas – two nurses who cared for a sick Ebola patient contracted the virus, making it the first known transmission of the Ebola virus in the United States. The Centers for Disease Control has a complete history of cases by year and by country.