What Is Ebola?

5 things to know about the disease as cases rise in Congo and Uganda

Rachel Nania,

AARP

Comments

Published May 21, 2026

A color-enhanced transmission electron micrograph showing the characteristic long, filament-like structure of an Ebola virus particle, curved and looped against a textured purple background.

Universal Images Group via Getty

The World Health Organization (WHO) has declared a public health emergency of international concern over an Ebola outbreak in the Democratic Republic of the Congo and Uganda. An estimated 139 people have died of the virus, and nearly 600 are suspected to have it, including one American doctor working in Congo who is now being treated in Germany. Global health officials warn these numbers will likely rise.

“One thing to get clear about where we are now is that this outbreak has gone on for a long time, probably months,” said Dr. Tom Frieden, president and CEO of Resolve to Save Lives and former director of the Centers for Disease Control and Prevention (CDC), in a May 20 webinar. “In other words, the virus has a big head start.”

While the risk to those in affected regions is high, WHO Director-General Tedros Adhanom Ghebreyesus says the risk globally is currently low.

Even still, U.S. health officials have alerted health care providers to the situation and have put in place enhanced screening measures and entry restrictions for some people who have traveled to the affected areas.

Two health officials speak at a panel during a World Health Organization news conference, seated at a white table with laptops and nameplates against a large blue WHO branded backdrop.

On 20 May 2026, WHO Director-General Tedros Adhanom Ghebreyesus hosted a press conference on the Ebola epidemic in the Democratic Republic of the Congo and Uganda.

Christopher Black/WHO

“As this fluid situation evolves, we are continuously gathering information and will aggressively adjust our response as needed,” Dr. Satish K. Pillai, the CDC’s incident manager for Ebola response, said in a news conference.

This is the 17th outbreak of Ebola in Congo since the virus was first discovered in 1976. The CDC says most cases in the country to date have occurred in people ages 20 to 39.

Ebola disease is caused by a group of viruses

Ebola disease is a severe illness caused by a group of viruses known as orthoebolaviruses. They were first discovered in 1976 in Congo and are primarily found in sub-Saharan Africa.

According to the WHO, three viruses are known to cause large Ebola disease outbreaks: Ebola virus, Sudan virus and Bundibugyo virus, which is the strain responsible for the current outbreak.

Fruit bats are thought to be the natural hosts of orthoebolaviruses. Humans can become infected if they come in contact with the bodily fluids of infected animals, such as fruit bats, chimpanzees, gorillas, monkeys, forest antelope or porcupines, the WHO explains.

It spreads through direct contact

Infected individuals can spread Ebola to others by direct contact with the blood or body fluids of a person who is sick with or has died from Ebola or by direct contact with objects or surfaces that have been contaminated with these things.

“It’s not casual contact; it’s not airborne,” WHO expert Lucille Bloomberg said in a May 20 news conference.

What’s more, a person isn’t considered contagious until after symptoms appear, the CDC says. The time from infection until the typical onset of symptoms for Bundibugyo virus ranges from two to 21 days.

Symptoms are severe and the disease can be fatal

Health experts describe the early symptoms of Ebola as “dry” symptoms, which can include fever, aches, pains and fatigue. “Wet” symptoms appear later and can include diarrhea, vomiting and unexplained bleeding.

Organ failure can also occur in the later stages of the disease, and the WHO says the virus’s impact on the central nervous system can result in confusion, irritability and aggression.

Lab tests can confirm an infection; however, Frieden explained, testing for the Bundibugyo strain is more complicated, which is one reason the outbreak has persisted for a while.

The average fatality rate for Ebola is around 50 percent.

There are no treatments for the Bundibugyo virus

Currently there is no federally approved vaccine or treatment for the Bundibugyo virus. (There is a vaccine for another Ebola strain.) In its alert to health care providers, the CDC said mortality rates may be lowered with intense supportive care and fluid replacement.

“There’s a lot of evidence that survival really increases with prompt treatment and supportive care,” Frieden said.

Risk remains low for Americans

U.S. health officials emphasize that the risk of Ebola to Americans is low at this time — “near zero,” Frieden said.

Still, experts are warning against nonessential travel to the affected areas. The State Department has issued a Level 4 travel advisory for both Congo and Uganda, advising Americans to avoid travel.

%{postComment}%