Ebola explainer with expert Dr. Steven Bradfute

The University of New Mexico Health Sciences Center Newsroom recently asked infectious disease expert Steven Bradfute, PhD, about Ebola viruses and the current Ebola outbreak in the Democratic Republic of the Congo and Uganda.

Bradfute is an associate professor in the UNM School of Medicine’s Department of Internal Medicine and associate director of UNM’s Center for Global Health. He is an expert in viruses known to cause significant harm to humans, including Ebola, equine encephalitis viruses and hantaviruses. He has worked in high-containment laboratories for 21 years.

As a postdoctoral fellow, starting in 2005, Bradfute worked on Ebola viruses at the U.S. Army Medical Research Institute of Infectious Diseases at Fort Detrick, Md. There, he studied how Ebola viruses bypass the immune response and worked on possible drug treatments that could work against Ebola.

Bradfute now runs a research lab where he works on early-stage vaccine development for Ebola viruses using non-infectious pieces of the virus. (UNM does not work with live Ebola viruses.)

What are Ebola viruses?

Steven Bradfute: Ebola viruses are a group of viruses that can cause hemorrhagic fever in humans. There are six species or types of Ebola virus, four of which are known to cause disease in humans.

The most prevalent species is Ebola Zaire, which was discovered in 1976 in Zaire (now the Democratic Republic of the Congo). Since it’s been discovered, it has caused roughly 37,000 infections. It was the species of Ebola virus that was responsible for the large outbreak in 2013 to 2016.

Next up is Sudan Ebola virus, the Sudan species, which has caused about 1,000 infections.

Third on the list is this Bundibugyo species, which was first discovered in Uganda in 2007. There was a second outbreak in the Democratic Republic of the Congo in 2012. That is the species that is currently circulating right now in the Democratic Republic of the Congo and Uganda.

The fourth species known to cause disease is Taï Forest Ebola virus, which infected one individual who survived, in Côte d’Ivoire, the Ivory Coast, in 1994.

What research does the UNM Health Sciences Center conduct on Ebola viruses, and why is that research important?

Steven Bradfute: We’re part of a consortium funded by the Department of Defense and run through Los Alamos National Laboratory called RAPTER (Rapid Assessment of Platform Technologies to Expedite Response). This is a program to try to be ready to develop vaccines rapidly against emerging pathogens. For the Ebola aspect of this, we provide some of the basic subunits for the vaccines that are going to be tested by other groups in this consortium.

What symptoms does the Bundibugyo strain of Ebola cause?

Steven Bradfute: A lot of the early symptoms are pretty similar to a lot of other diseases. This could be headache, being extremely tired, stomach pain, muscle aches, a fever, a rash. That can be followed by severe vomiting and diarrhea, which can lead to even more severe complications.

The way the virus attacks is it infects immune cells in your body, and it shuts down the ability to make a rapid early immune response, and that leads to the virus proliferating. Then your immune system overreacts, and you get a very broad inflammatory response, which triggers clotting of your blood until you can’t clot anymore, so you get blockage of very small blood vessels in your organs. That leads to organ shutdown, and the virus actually damages the organs directly as well, so it’s a multi-pronged disease.

How does Bundibugyo spread?

Steven Bradfute: It spreads through body fluids—blood, sweat, tears, vomit, feces. It’s in bedding that gets contaminated with body fluids. In some cultures, when people perish from Ebola virus or any other disease, there’s a ritualistic washing of the body and kissing of the body, and so the virus can transmit in those ways. Health organizations work with these communities to keep their traditions but do it safely. Viral spread is not airborne.

How contagious is Bundibugyo?

Steven Bradfute: It’s not as contagious as, for example, flu or COVID, but it is more contagious than, say, hantavirus.

What’s the mortality rate of Bundibugyo?

Steven Bradfute: The lethality rate is still being ascertained in the last two outbreaks. It looks like it’s between 25% and 50%. We’ll know more, unfortunately, as this outbreak progresses. From the data we have right now, it’s around 25–27%. We’ll see whether that changes. The Zaire species of Ebola virus, which is more prevalent, used to be thought to be close to 90% lethal, but with the recent outbreak about 10 years ago, the average mortality rate of that species is about 42%.

The World Health Organization has stated there are no vaccines or therapeutics available for Bundibugyo. Is it realistic to expect an approved vaccine or drugs? How long might those take?

Steven Bradfute: For Ebola Zaire species, there are two vaccines and two drugs that are used in humans. Unfortunately, these don’t protect against the Bundibugyo species. There are vaccines and drugs that have been shown for Bundibugyo to be effective in animal models, and so there is great interest in putting these into human clinical tests as soon as possible. That will depend on how available these vaccines and drugs are. Are they available? And is the material available that has been produced at facilities that make it safe for them to put in humans? Those conversations are ongoing.

What type of care does an Ebola patient receive?

Steven Bradfute: Unfortunately, for Bundibugyo, supportive care is the only thing that can be done to treat patients. That can be things like making sure you have good fluid levels in the body, regulating blood pressure and giving oxygen if needed.

How can someone prevent getting an Ebola infection?

Steven Bradfute: Ebola is endemic primarily in Africa. Basically, the transmission often occurs because certain types of fruit bats carry Ebola. It can also spread if someone eats bushmeat—animals that are killed in the forest, like monkeys. Eating contaminated meat can cause infection.

To limit spread, it’s basically isolating individuals who are sick, and if there are healthcare workers treating them, wearing a lot of good personal protective equipment to stop transfer of body fluids, either through splashing or direct contact. If it’s a household contact, again, it’s just staying out of touch with body fluids, any sort of bedding, or anything like that that’s been in touch with these body fluids.

How big could this new outbreak in Africa get?

Steven Bradfute: It’s a good question. It got pretty big before it was identified that it was actually an Ebola virus. So, the key is going to be isolating individuals who are sick, and then finding out who they’ve contacted, then, trying to isolate those individuals if they get sick. Both the Democratic Republic of the Congo and Uganda have done this multiple times with multiple Ebola outbreaks in the past. The problem is some of these areas where the virus is spreading, there’s some warfare, which can impact infrastructure and access for public health work.

What is the risk from this Ebola outbreak to everyday Americans?

Steven Bradfute: The biggest Ebola outbreak example we have is the large Ebola Zaire outbreak from 2013 to 2016 that was primarily in Liberia, Guinea and Sierra Leone. People traveled from those areas when they were infected, and it was spread in different areas throughout the world. We did have individuals who were sick that came to the United States, and there was very limited transfer to other individuals in the U.S., because we really stayed on top of isolation and contact tracing. So, I think the question is going to be, how far has this virus spread—which we don’t know at this point—and then if it spreads to other areas, just making sure that we have isolation and contact tracing. With proper public health measures, it can be controlled. But it is something to be taken very seriously, and something we need to be vigilant about.

Should Americans do anything different in their day-to-day lives right now?

Steven Bradfute: No. I would just say, if you’ve traveled to Uganda or the Democratic Republic of the Congo, it’s smart to think about, ‘OK, was I in contact with anyone that was sick?’ If you are sick and you go to the doctor, let them know you have this travel history so that they can look at this. The virus isn’t prevalent right now, that we know of, through the entirety of both of those countries. Right now, there are certain regions where we know the virus is, and that’s something to keep in mind as well.

What do you see as similarities and differences between this 2026 Ebola outbreak and past Ebola outbreaks, such as the large outbreak in West Africa from 2013 to 2016?

Steven Bradfute: What we know is the different Ebola virus species are fairly similar when it comes to the disease that they cause and how they can be controlled. So, regardless of whether it’s Sudan, Bundibugyo, Zaire, Taï Forest—if you do isolation and contact tracing, that’s been shown to be effective at limiting spread. And then, with the exception of Zaire, we don’t have treatments for these other viruses, other than supportive care. So, there’s nothing about this outbreak that we know of so far that makes it particularly different from previous outbreaks with Ebola, but it’s just important to really use public health measures to control spread.

I will say one more thing about that. There were vaccines and therapeutics during the large 2013 to 2016 Ebola Zaire outbreak that were implemented toward the end of that outbreak and are now approved for use in human studies, because they were able to test and compare different drugs and vaccines on the ground during the outbreak. I know that researchers and clinicians will be looking to see if there are available vaccines and therapeutics against Bundibugyo to put into humans—because we know some have been effective in animal models. If they can be used in humans, we do have a blueprint on how to test them safely and scientifically from the 2013 to 2016 outbreak.

Can you draw any conclusions from the fact that the world is experiencing two concurrent outbreaks of relatively rare viruses—hantavirus and Ebola?

Steven Bradfute: I think it’s a good question. There doesn’t appear to be any link between the two. They’re rare viruses that are occurring at the same time, but there’s no causal link that suggests that there’s anything at play that caused them both to occur at this time. They’re both following similar characteristics of these viruses as outbreaks we’ve seen in the past.

Are there any concerns about another pandemic?

Steven Bradfute: I think it’s going to be trying to isolate and contact trace the individuals that are sick in Uganda and the Democratic Republic of the Congo. At this stage, I think we don’t quite know how big the outbreak is and how many cases that we’re missing. So, that’s going to be a very active area of surveillance. That’s going to be an international collaboration to do this. So, until we know that, we don’t know if this is going to be an outbreak the size of what we saw in 2013 to 2016 or not. At this point it’s just not something that we can really predict.

Could it end up being the size of coronavirus in 2020?

Steven Bradfute: We don’t have any indication that this virus (Bundibugyo) spreads through airborne transmission. None of the previous Ebola outbreaks have, so I’m not as concerned about something that spreads like COVID, or flu or measles, where it’s extremely widespread. It’s still being spread, as far as we know, through body fluids, and isolation and contact tracing work. So, I’m not concerned about a pandemic at this point that can spread as easily as what we saw in COVID, for example.

Are there Ebola viruses that occur naturally in the U.S.?

Steven Bradfute: I’d like to let people know that Ebola viruses are not naturally found in the United States, so this isn’t something that we’re concerned about coming from the U.S. If there are individuals who enter the U.S. that are infected, the key will be to identify infection and do isolation and contact tracing. We have the tests in the United States to detect this virus, and we have the public health measures to isolate and contact trace. So, I think it’s important for people to know that it’s not something they will get from bats here in the United States, because the bats we have are not known to carry this virus.