Ebola Disease: Types, Symptoms, How It Spreads, Prevention and Treatment

Ebola disease is caused by a group of viruses called orthoebolaviruses (formerly ebolaviruses). They can cause serious illness that, without treatment, can be fatal — with a death rate as high as 80–90%. The viruses were discovered in 1976 in the Democratic Republic of the Congo, and are found mainly in sub-Saharan Africa.

Image from CDC’s page.

Types

Four orthoebolaviruses cause illness in people:

• Ebola virus (Orthoebolavirus zairense), which causes Ebola virus disease;
• Sudan virus (O. sudanense), which causes Sudan virus disease;
• Taï Forest virus (O. taiense); and
• Bundibugyo virus (O. bundibugyoense).

Two others have not made people sick so far: Reston virus has caused disease in monkeys such as macaques, and Bombali virus was more recently found in bats.

Symptoms

Illness can begin 2 to 21 days after contact with the virus, most often after 8 to 10 days. Early symptoms are “dry”: fever, aches, pains and fatigue. As the illness worsens it usually turns “wet,” with diarrhea, vomiting and unexplained bleeding.

How it spreads — and how it doesn’t

Ebola spreads through contact with the body fluids of a person who is sick with it or has died of it. People are contagious only once they have symptoms. Rarely, people catch it from an infected animal, such as a bat or a nonhuman primate.

Ebola does not spread like flu or COVID-19. It is not airborne: you cannot catch it just by being near someone or passing them in a public place. The people at highest risk are health care workers and family members who care for a sick person without proper infection control. The viruses pose little risk to travelers or the general public.

Prevention

In or traveling to areas where Ebola has been diagnosed or is suspected:

• Avoid body fluids of sick people — blood, urine, feces, saliva, sweat, vomit, breast milk, amniotic fluid, semen and vaginal fluid — and the semen of someone who has recovered until tests show the virus is gone from it.
• Avoid contaminated items: clothes, bedding, needles and medical equipment that may have touched an infected person’s blood or fluids.
• Avoid the body of anyone suspected or confirmed to have died of Ebola, including during funeral and burial rituals.
• Avoid bats, forest antelopes and primates, and blood, fluids or raw meat from these or unknown animals.
• Wear personal protective equipment if you have contact with sick or dead patients, their fluids, or objects covered in them.
• Watch your health for 21 days after returning from an area with an outbreak, and get medical care at once if symptoms appear.

Vaccine

The Food and Drug Administration has approved ERVEBO® to prevent Ebola disease caused by Orthoebolavirus zairense only. It is recommended for U.S. adults 18 and older who may be exposed to the virus.

Diagnosis and treatment

Doctors diagnose Ebola in living patients with a PCR blood test; blood tests for antibodies can show a recent infection. Anyone being tested should be kept apart from others in the health care facility until results are confirmed.

Two FDA-approved drugs, Inmazeb™ and Ebanga™, treat Ebola disease caused by Orthoebolavirus zairense only. For every patient, supportive care greatly improves the chance of survival:

• fluids and electrolytes, by mouth or intravenously;
• medicine to support blood pressure, reduce vomiting and diarrhea, and manage fever and pain; and
• treatment of any other infections.

Sources

Based on "Ebola Disease Basics," Centers for Disease Control and Prevention; a work of the United States government in the public domain.