Leisha Nolen, a 37-year-old pediatrician and genetics researcher by training, currently works as a “disease detective” for the Centers for Disease Control and Prevention. She is one of about 60 members of the agency’s Epidemic Intelligence Service (EIS), a two-year post-graduate program that prepares health professionals to respond at a moment’s notice to outbreaks around the world.

On Saturday, Nolen will leave for her second month-long trip this year to the Ebola-affected areas of West Africa as part of an international effort to stem the devastating outbreak there. She spoke with The Washington Post on the eve of her departure about the work that lies ahead. The transcript that follows has been edited for length and clarity:

WP: Tell us about your trip [to Africa] earlier this year — where you went, what you saw.

1 of 64 Full Screen Autoplay Close July 2014 June 2014 April 2014 March 2014 Skip Ad × West Africa struggles to contain Ebola outbreak View Photos United States issues travel warnings against visiting Sierra Leone, Liberia and Guinea as virus’s death toll climbs. Caption Countries around the world work to help patients and take precautions to prevent the disease from spreading. Aug. 16, 2014 People watch as a crowd protests before entering the grounds of an Ebola isolation center in Monrovia, Liberia. A mob of several hundred people chanting, “No Ebola in West Point,” opened the gates and took out the patients, many saying that the epidemic is a hoax. Just moments before, they drove away a burial team that had tried to take away the bodies of four deceased residents. The isolation center, a closed primary school originally built by USAID, was being used by the Liberian Health Ministry to temporarily isolate people suspected of carrying the virus. John Moore/Getty Images Buy Photo Wait 1 second to continue.

Nolen: I went to Liberia approximately two months ago. I was there for a month. I went in response to this current Ebola outbreak. I was actually there sort of in a lull between cases. I happened to arrive after the last case had passed away. I was there for a full month, and during that month there were actually no new cases. So it was this period when things looked to be turning the corner. Things seemed to be getting better.

What we were involved in while we were there was really education, getting people to understand what to look for in case more cases came across the border, hoping to create a system where they’d be aware if any new cases arrived, in the hopes they’d be able to catch them quickly and prevent spread. Unfortunately, that didn’t take full effect. After I left, about a month later, the new cases came through into Liberia.

WP: What has it been like to watch that spread happen from here in recent days?

Nolen: It’s amazing and terrifying. This is a huge outbreak. This is much larger than what we’ve ever seen before for Ebola. It’s devastating to these communities. I was up in Foya, which is the community that’s been really hard hit in Liberia. It’s this really small, tight-knit community, and people really trust and know each other very well. To have this come through and just devastate their population is just horribly tragic.

WP: Where are you going this time, and what’s your mission, your goal for this trip?

Nolen: I’m going to Sierra Leone tomorrow. There have been a few people on the ground from CDC in Sierra Leone the past few weeks, but there hasn’t really been a team large enough to really help the public health system there work out how to do this. There are going to be eight of us going. We’re really going to try to help the government to understand the best ways to control this.

It will be a lot about “contact tracing,” which means following people who had contact with Ebola patients. You get Ebola through direct contact with body fluids, so the people who are most likely to get the infection are those people who are very close to the current Ebola patients. So you try to figure out who Ebola patients have had contact with. From there, you try to monitor those patients very closely for symptoms. As soon any get symptoms, you isolate them off and prevent them from spreading it to a next round of people.

Another thing we’re going to work on is communication and trying to get people to understand what this infection is about and how it’s transmitted. A lot of people in West Africa right now don’t know what to believe or who to believe. Certainly, we’d like to help clarify some of that and do what we can to make people understand why the infection is occurring.

WP: When you’re on the ground in a place like this, with an outbreak like this, what are the obstacles to tracing this disease and trying to halt its spread?

Nolen: One of the obstacles while I was in Liberia is a cultural disbelief in the infection. In one family specifically that I worked with, their mother had died of Ebola. She’d gone into the hospital and was very clearly an Ebola patient. But to the family it just seemed like she got whisked away by the foreign doctors, put into a hospital, and they really didn’t see her again. They didn’t believe this was Ebola. They thought this was maybe a hoax or something that was being done to take advantage of them. It took a long time, sitting and talking with them, trying to understand their perspective of it and trying to get them to understand what had happened in reality.

So I think a large hurdle is working with that [skepticism] and getting people to accept this idea of what the infection is, and that it is a true infection and not some sort of way to trick them or take advantage of them by the government or by the foreigners.

WP: Describe the role you are playing there. Why is the tracing of the disease as important as even the treatment of people who are already ill?

Nolen: The treatment, of course, helps the people who are sick right now. But if you want to stop an infection, you have to stop new people from getting sick. If you don’t do contact tracing, one person will get sick, they’ll give it to their next-door neighbor or to their family. And those people, 10 days later, they’ll get sick and give it to the next group of people.

The idea of contact tracing is to cut that off. If any new people start to have symptoms, we isolate them and stop them from coming into contact with new people. And therefore they don’t continue the chain onward and onward.

WP: What precautions do you take yourself? And what fears, if any, do you have of walking into a region that’s in the middle of an outbreak?

Nolen: Certainly, it makes everyone nervous. I think you’d be silly not to be nervous. But it is an infection that’s transmitted by bodily fluids. So it’s not something you’re going to get by being in the same room as someone or simply talking to someone.

In situations where you’re in a village or neighborhood, you avoid sharing cups or sharing silverware. If I go in anywhere I have a higher index of suspicion, if I think it’s more likely that there are people able to pass along the disease, I am taking along gloves, gowns, masks. I want to be safe. So I have the option of wearing those if I think the occasion arises that I need them.

WP: Does your own family have reservations about your going back?

Nolen: I can’t say my mom is very happy, no.

WP: There have been fears expressed back here [in the U.S.] about Ebola, especially with some [American] patients heading back [for treatment in Atlanta]. Given what you know about how the disease spreads and having worked with it, do those fears seem unwarranted?

Nolen: I can understand why people [here] are nervous. It’s a disease that sounds terrible. It’s a disease that actually is terrible. But like I was saying earlier, it’s an infection that’s spread through bodily fluids. People are not infectious before they start to have symptoms. Until people become actually ill, you cannot get an infection from someone else.

WP: As you head back [to Africa] tomorrow, how confident are you that this outbreak can be brought under control, at least eventually?

Nolen: The key word there is eventually. This is a long haul. This is not going to be quick. I can’t imagine I’m going to go and fix it, though I would love to say I did. It’s going to be multiple months of multiple teams of people from CDC and other organizations going over there and doing their best, helping people understand and helping the health system there get a handle on this.