An expanding Ebola outbreak in Uganda has prompted U.S. officials to be on guard against the deadly virus and to screen some people arriving from Africa.

There are no confirmed Ebola cases in the U.S. yet. But health experts with the U.S. Centers for Disease Control and Prevention are working closely with local and state health officials throughout the U.S. to monitor people who have flown into the country after traveling through Uganda.

In Colorado, health officials are tracking multiple people who recently arrived from high-risk areas. These people take their temperature daily, keep tabs on their health and report any symptoms of illness to officials with the Colorado Department of Public Health and Environment.

The current Ebola outbreak is related to what’s known as the “Sudan strain,” but the virus is spreading in Uganda. It’s worrisome because previous Ebola vaccines and treatments do not work against this strain, and the virus can kill as many as half of those who get it. Furthermore, Ebola now is spreading in Kampala, Uganda’s capital, which is a densely populated city of more than 1.3 million people.

While the risk of getting Ebola in the U.S. is extremely low, health experts are keeping a close eye on the Uganda outbreak and have plans in place in case anyone with suspected Ebola arrives in the U.S.

To answer your questions about Ebola, we consulted with Dr. Michelle Barron, senior medical director of infection prevention and control for UCHealth and one of the top infectious disease experts in Colorado.


Why is Ebola so frightening?

“Mortality is high,” Barron said. “Somewhere between 40 and 50% of people who get it die. So, this is not insignificant.”

Should the average person in the U.S. be worried about Ebola?

No. The average person in the U.S. doesn’t need to worry about Ebola.

“The likelihood of us seeing a patient is next to zero. But if we did, we have many trained people with a lot of experience to manage this appropriately,” said Barron, who is also a professor at the University of Colorado School of Medicine on the Anschutz Medical Campus.

When was Ebola last a concern in the U.S.?

Ebola was last a concern in the U.S. in 2014 and 2015. At that time, an Ebola outbreak in West Africa sickened more than 27,000 people. More than 11,000 of them died. That outbreak was the largest so far.

A man who had traveled from West Africa to Dallas, Texas died of Ebola on Oct. 8, 2014. Two health care workers who treated the man contracted Ebola but survived. Altogether, 11 people were treated for Ebola in the U.S. during the 2014-2015 outbreak. Of the 11 (including the man from Dallas) two died. The others recovered.

Due to that Ebola outbreak, health experts across the U.S. developed plans and protocols to prepare for Ebola patients. They also learned how health workers could safely care for Ebola patients.

That’s why health experts are ready again if someone with Ebola or suspected Ebola arrives in the U.S.

“We can manage this because of all the training we did in 2015. That helped us prepare for COVID-19, and we just keep layering upon our expertise,” Barron said.

What is Ebola?

“Ebola is a hemorrhagic fever virus,” Barron said.

The virus is common in animals. It was first discovered in humans in 1976 near the Ebola River in what is now the Democratic Republic of Congo. That’s how the virus got its name.

According to the experts at the U.S. Centers for Disease Control and Prevention (CDC), scientists do not know where the Ebola virus first came from, but it’s likely that it spread from a bat or a non-human primate to humans.

How does Ebola spread?

The virus spreads in people through direct contact with bodily fluids like blood or other bodily fluids.

“This can be contact with saliva, blood, semen, emesis (from vomiting) or diarrhea,” Barron said.

Family members or health workers who care for people with Ebola can be infected if they are exposed to bodily fluids then touch their eyes, nose or mouth. Ebola can also spread through sexual contact with an infected person.

The disease is most transmissible once a person becomes sick rather than during the incubation period.

How long is the incubation period between exposure to Ebola and sickness?

Ebola has a much longer incubation period than some other infectious diseases like COVID-19 and the flu, Barron said.

“The average is about 7 to 10 days, but it can be up to 21 days. And so, there’s a really long incubation period. And that makes this challenging,” she said.

How transmissible is Ebola?

“Ebola is highly transmissible,” Barron said. “It’s more transmissible in what’s known as ‘the wet phase’ rather than ‘the dry phase.’ During the dry phase, people have fever, chills, body aches, that sort of thing. The wet phase is when people start having issues with bleeding, vomiting and diarrhea. That’s when they’re most infectious.”

Is the spread of Ebola similar to the way that the virus that causes COVID-19 spreads from person to person?

No. The virus that causes COVID-19 is a respiratory virus. It spreads through respiratory droplets. These droplets can stay suspended in the air or can contaminate objects and remain infectious for a short time. People can spread COVID-19 when they sneeze or cough. It is also possible for people who are asymptomatic to spread COVID-19. Ebola, on the other hand, spreads much less easily than COVID-19. But it is also much deadlier, killing as many as half of people who are infected.

How is this Ebola outbreak different from previous Ebola outbreaks?

The outbreak in 2014 and 2015 came from a different strain of Ebola, known as the Zaire strain.

“The current one is the Sudan strain, and the reason that matters is because the vaccine we currently have available against Ebola doesn’t work for this particular (Sudan) strain.”

Are there effective treatments for Ebola?

Yes, there are some treatments, but they are not effective against the Sudan strain.

“The therapeutics we used for the last outbreak don’t work for this particular strain,” Barron said.

CDC officials are sending monoclonal antibodies to Uganda to help with the current outbreak, but it’s unclear how helpful the treatments will be.

What is happening with the Ebola outbreak in Uganda now?

“The concern about the outbreak in Uganda is that it originally started in some of the more rural areas, but there have now been 17 people who have been identified as having Ebola in the city of Kampala,” Barron said.

The spread of the virus in a larger, more densely-populated city increases the likelihood that the virus will continue to spread.

How many people have gotten the virus in the current Ebola outbreak?

As of early November, there have been 131 confirmed cases of Ebola during this outbreak, and 48 people have died, according to the World Health Organization. That’s a fatality rate of 37%.

Among those who have been sickened, at least 18 have been health care workers. Six of them died.

Why is this strain called the Sudan strain?

The Ebola strain now causing the outbreak in Uganda can be traced back to an outbreak in Sudan in 1976.

Researchers have thus far identified six strains of Ebola. They include the Zaire, Bundibugyo, Sudan, Taï Forest, Reston and Bombali strains, according to the World Health Organization.

There have been seven previous outbreaks of the Sudan strain. Four occurred in Uganda and three in Sudan.

How does the CDC’s tracking system work for people who have traveled to the U.S. from Uganda?

The screening protocols are similar to those used in 2014 and 2015 during the previous Ebola outbreak, Barron said.

Since late September, travelers who are arriving in the U.S. from Uganda are flagged for interviews when they come through passport control.

“Currently, about 140 people a day enter the U.S. from Uganda,” according to CDC health officials.

The U.S. has not restricted travel from Uganda. But officials have implemented health screenings when passengers arrive at five domestic airports. They include: Chicago O’Hare, Hartsfield-Jackson in Atlanta, John F. Kennedy in New York, Newark Liberty and Washington Dulles.

“When they go through these airports, they get asked additional screening questions,”  Barron said. “They’ll ask you, ‘Are you feeling well? Have you had any known exposures to someone who was sick in Uganda? What were you doing? Were you exposed to any health care workers? And so on.”

A list of all of these people is then sent to the states where person is residing or staying in the U.S. Then local and state health officials continue to check in with the recent travelers and monitor them if they become ill.

Most of the travelers are at very low risk for getting Ebola, Barron said.

Even if a recent traveler gets sick, Barron said it’s much more likely that they will have COVID-19, the flu or RSV, the current respiratory viruses that are spreading widely throughout the U.S. and globally.

“Of course, if you were a health care worker and you were working in an Ebola treatment center, then that’s a different story,” Barron said. “They are considered high risk, and that person would need to isolate for 21 days.”

Are there vaccines for Ebola?

Yes. There is a vaccine for Ebola. It helps prevent the previous Zaire strain of Ebola that caused the outbreak in 2014 and 2015, but unfortunately does not work against the current Sudan strain.

The U.S. Food and Drug Administration approved the Ebola vaccine in 2019. It’s known as Ervebo or rVSV-ZEBOV.

There is no approved vaccine that fights the Sudan strain of Ebola, but U.S. health officials sending doses of an experimental vaccine to Ugandan health officials.

Scientists at the U.S. Institutes of Health and the Sabin Vaccine Institute have developed a small number of doses of a vaccine that may help fight the current outbreak. They are working to send as many as 9,000 doses to Ugandan health officials.

How are health care workers in the U.S. preparing for Ebola?

Experts in the U.S. have been preparing for possible cases of Ebola with this outbreak since September when the World Health Organization issued alerts about the new outbreak.

There are designated hospitals in each part of the country with special treatment units where providers can safely care for patients with Ebola.

At UCHealth’s clinics and hospitals, providers keep all patients safe by asking screening questions designed to flag potential concerns about Ebola.

“Everyone who enters our buildings, whether it’s through an emergency department or through a clinics, gets asked a question about travel. You’re asked, ‘have you traveled outside the United States in the last 21 days?’”

For those who have not, the screening ends.

Anyone who has traveled to Uganda now will be flagged for additional questions. Staff members know to take anyone at high risk for Ebola into a room where they can be isolated and providers can put on personal protective equipment to examine the patient.

“If we have anyone with a travel history (of concern) and symptoms, then we activate our emergency preparedness plan,” Barron said. “That doesn’t mean people need to panic. It means we need to get a better, more detailed health history and ask, ‘What are your symptoms?’  ‘What were you doing in Uganda?’ ‘Where, specifically, were you?’”

If hospital workers or other health officials flag any concerns with patients or recent travelers, experts can arrange for Ebola testing.

Again, the likelihood is much higher now that a person has a more common illness, Barron said. But she and other infectious disease specialists are bracing for an Ebola patient, just in case.

Editor’s Note: During the pandemic, the Colorado Times Recorder will occasionally post articles from UCHealth Today, which is published by UCHeatlh, the hospital associated with the University of Colorado School of Medicine. Our goal is to provide as many people as possible with accurate information about the virus and related topics.