Ebola Outbreak: What to Know About Symptoms, Spread, and Risk

A recent outbreak of Ebola in parts of the Democratic Republic of the Congo and Uganda has gotten global attention, prompting the World Health Organization (WHO) to declare a public health emergency of international concern.

But what does that mean—and should people in the U.S. be worried?

Jessica Justman, MD, an infectious disease specialist and epidemiologist at Columbia, explains the disease and breaks down the risks.

What is Ebola?

Ebola is a rare but severe viral disease found primarily in sub-Saharan Africa. It can cause serious illness, progress quickly, and is often fatal, even with treatment.

What are the symptoms of Ebola?

Symptoms typically begin seven to 10 days after exposure but can take up to three weeks to appear.

Early symptoms often include:

• Fever
• Body aches
• Fatigue

As the illness progresses, symptoms can become more severe, including:

• Diarrhea
• Vomiting
• Internal bleeding
• Bleeding from the gums or rectum
• Coughing up blood

“These later symptoms are what make Ebola especially dangerous and difficult to manage,” says Dr. Justman.

How does Ebola spread?

Unlike illnesses such as the flu or COVID-19, Ebola is not thought to be airborne. However, it is highly contagious through direct contact.

People can become infected through:

• Bodily fluids (such as saliva, blood, vomit, diarrhea, or semen)
• Contaminated clothing, bedding, or personal items
• Contact with someone who is sick—or who has died—from Ebola

How dangerous is this Ebola outbreak?

The current outbreak is caused by the Ebola Bundibugyo strain, which has a mortality rate of about 50 percent.

It is relatively rare and has caused only a few outbreaks in the past—but this is the largest recorded outbreak of this strain, with hundreds of infections reported.

There is currently no approved vaccine for the Ebola Bundibugyo strain.

Are there treatments for Ebola?

There is no specific antiviral treatment for Ebola Bundibugyo. However, early medical care can make a difference.

“Supportive care—like fluids, electrolytes, oxygen, and medications to stabilize blood pressure and manage symptoms—can significantly improve survival, but even with supportive care, it remains a very serious illness,” Dr. Justman says.

Is there a risk in the U.S.?

Currently, Ebola is not present in the United States, and the risk to the general U.S. public remains very low.

Public health officials are closely monitoring the situation and taking steps to prevent spread, including travel-related precautions and screening measures. Staying informed—and relying on trusted public health guidance—is key.

Jessica Justman, MD, is Senior Technical Director at ICAP, a global public health center at the Mailman School of Public Health at Columbia University.