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Eight Ebola questions, answered

Dr. Daniel Bausch tells msnbc why Ebola isn't a threat to the United States, but is spiraling out of control in West Africa.
A paramedic from the fire department looks on after showing the media how to put on a protective suit, in Panama City October 2, 2014.
A paramedic from the fire department looks on after showing the media how to put on a protective suit, in Panama City October 2, 2014.

Dr. Daniel Bausch is an associate professor in the Department of Tropical Medicine at Tulane University, and a former member of the CDC Special Pathogens Branch with experience with Ebola. He spoke recently with msnbc by phone from Peru, where he is currently the director of the Emerging Infections Department at the U.S. Naval Medical Research Unit 6 in Lima.

MSNBC: This Ebola outbreak is the largest we’ve had – it’s spread to more countries than ever before and already killed more people than all previous outbreaks combined. First, what is Ebola? How is it spread?

BAUSCH: Ebola is a virus believed to be maintained in the fruit bat population, which occasionally spreads to humans through contact with their blood, feces or bodily fluids, or indirectly through other, non-human primates, such as monkeys or chimpanzees that have become infected.

Our main problem with the virus is when humans become infected in places like West Africa, where there isn’t the public health infrastructure to interrupt transmission between people – where you don’t have the clean equipment and needles and so on as you would in the United States. That’s when you see this kind of amplification, which in this case has created a humanitarian disaster in parts of West Africa.

MSNBC: You mentioned the humanitarian situation in West Africa. The number of infections and deaths are still growing exponentially. Why has this outbreak in particular been so much worse than those in the past?

BAUSCH: I think it’s multifactorial. First of all, the countries involved are some of the poorest on the planet. If you look at United Nations development indices, Sierra Leone, Liberia and Guinea are places with poor governance and underdeveloped infrastructure. Two of these countries are coming out of long civil wars; Guinea has had its share of civil unrest.

Photo essay: Ebola continues its deadly march

There are biologic principles, of course, that dictate where Ebola virus may be found and where it is introduced, but it is very, very clear that if you look at where it spreads, it spreads in areas where the public health infrastructure has been decimated. When you look at where this Ebola outbreak has occurred – and before that, outbreaks of Ebola and its sister virus, Marburg, in Angola, the Democratic Republic of Congo and northern Uganda, where the Lord’s Resistance Army has been active for years -- these are all places where we’ve seen the public health system decimated by civil unrest. That’s the underlying factor in why we have such a major problem in West Africa.

"Each time there’s a case of Ebola, it’s essentially like opening up a new front in a war."'

Adding to that, you have the unique situation of Ebola spreading in a part of the world where there’s a lot of unregulated cross-border traffic between populations -- ethnic groups that live on both sides of the border and frequently travel back and forth. People live in one village and then on market day they go to a village on the other side of the border. That adds to the complexities, and in this particular case it’s also gotten into urban areas, which adds another layer of challenge to control.

Each time there’s a case of Ebola, it’s essentially like opening up a new front in a war. With every new case you need a center where you can isolate and treat a person, doctors and nurses and equipment and the personal protection you need -- gowns and gloves and so on -- as well as a contact tracing team composed of people in the community who can go out and monitor people who've been in contact with an Ebola patient, and to isolate and care for them if they get sick too. You need logistics, and social outreach to tell people how to deal with loved ones' bodies at funerals when someone dies of Ebola.

It takes a lot of resources to do that in one area. Then, if there's another outbreak -- say, 500 kilometers away in a rural region -- you have to open another front, and then another. Each new place with an outbreak forces you to start again, and potentially, we've outstripped our capacity to do that. We have to regain our momentum and rebuild our capacity to respond. 

MSNBC: Obviously the challenges are completely different in the United States, where we have a much stronger health infrastructure. But can you talk a little bit about how contract tracing works and how the CDC will be proceeding now that we have an Ebola case here in America?

BAUSCH: Contract tracing is pretty simple. It’s not high tech. When we have a case of Ebola, we talk to that person, we try to get a list of all the people with whom they’ve had direct contact during the period of their illness – not during the incubation period, when they’re not infectious, but while they’ve been sick – and then we try to identify each of those people. The longest incubation period is 21 days – that’s longer than it is in most people, for most it’s on the order of 8-10 days, but we use 21 days as a conservative estimate. We visit all those people every day and take their temperature. If every day their temperature is normal, then after 21 days we say ‘You’re not infected with Ebola, have a nice life.’

"I don’t foresee the worst-case scenario – you know, having tens or hundreds of thousands of cases of Ebola in the United States – that’s extremely unlikely."'

On the other hand, if they develop a fever, then of course we would react quickly to test that person for Ebola and isolate them if they test positive, and give them the best care we know how. These are classic epidemiological, public health principles that we use. We know how to do them. We’ve done it many times before in previous Ebola outbreaks, and it’s something that shouldn’t pose an extraordinary challenge to us here in the United States.

But I can imagine that it could become more complicated if you had you had someone who traveled internationally while they were sick and had close contact with numerous people on a plane, and then traveled to another airport and got on another plane, and so on. Then you would have potential contact with people dispersed across the country and throughout the globe.

MSNBC: We’ve been lucky so far in that the only infected person who has arrived here in the United States was not sick while on his flight. But as you said, it’s possible that someone who is contagious could get on a plane and spread the virus to other places around the world. What is the worst-case scenario that people like yourself are thinking about?

BAUSCH: I don’t see the worst-case scenario as being something that would directly impact the United States. Indirectly yes, as we live in a global community – we’ve not immune to the humanitarian and economic fallout this would have in West Africa. Our first concern of course is morbidity and mortality, but after that there is the financial impact of these countries stalling their economic development.

Unbridled transmission through large swaths of sub-Saharan Africa would have huge impacts in terms of the number of sick and dying but also in economic effects beyond that. We’re all interconnected in that way, perhaps much more so than we realize. I don’t foresee the worst-case scenario – you know, having tens or hundreds of thousands of cases of Ebola in the United States – that’s extremely unlikely.

MSNBC: What’s the possibility that the virus could mutate to become transmissible by air? Is that something that you worry about?

BAUSCH: People talk about it and there’s differences of opinion, but I think that’s also very unlikely. There are some mutations that happen with any virus as it gets transmitted, and that’s something we keep track of, but I can’t think any example of a pathogen that has mutated and rapidly changed its fundamental biology in that way. It's an extremely rare occurrence. 

MSNBC: There are a couple different strains of Ebola – do we know which strain it is that’s arrived in the United States, and is that the same strain we’re seeing in different parts of Africa? Is there variation in terms of morbidity and mortality?

BAUSCH: This is a strain, or more accurately, a species that we call Zaire Ebola virus. It’s consistently associated with the highest mortality rates of all the Ebola species. In some cases it's been up to 90% fatal, though we’re seeing slightly lower rates in this outbreak. But you have to take all that with a grain of salt, because there are other things that impact that rate.

Certainly the level of care people receive is one thing that can effect mortality, but there is also the problem of infected people who don’t want to come to the hospital out of fear. As you know, there are rumors circulating in West Africa that Ebola is being intentionally introduced, or was fabricated by the government to control the population, which makes it hard for international groups to do their research and aid work. So you can see a scenario where a sick person might not come to the hospital to be treated, and then their death isn't counted as being on the books, making the fatality rate seem lower than it is.

In this particular case, the numbers that we’re seeing in terms of fatalities are ranging from about 50% to around 75% -- similar to what we’ve seen in other outbreaks of this disease.

MSNBC: There are nearly 200 American military and health workers already on the ground in West Africa, and more than 3,000 troops still on their way. Do you think those U.S. efforts will be impactful? Are you optimistic?

BAUSCH: I’m supportive of the Obama plan. We really need to mobilize personnel and resources, and the United States is doing the right thing to do that.

That being said, we’re all late in addressing this and it’s gotten out of control. The analogy I’ve been using is this: You can say you want to send a man to the moon tomorrow and it'll cost $7 billion -- fine. You've got the money. But you still have to find and train people. Having the commitment and the desire and the money isn't enough. No one is going to be standing on the moon tomorrow.

"Unless you're in a setting where you’re a healthcare worker or a family member caring for a person who is sick, you probably couldn’t get Ebola if you wanted to."'

It’s a little like that with this outbreak. We're starting to see the commitment from the United States and other partners but the implementation is still incredibly challenging. Especially in this area of the world, where resources are so limited and there are so few people who are really familiar with dealing with this disease. We can send in 3,000 troops who understand weapons, and protection and military strategy -- we have that ready-made capacity -- but nobody is prepared for an Ebola outbreak.

It doesn't matter if you're talking about CDC or WHO, no one really has the capacity that deep to mobilize the personnel to take on an outbreak if it's tens of thousands of cases. Where do you get the personnel from, when there's not that many doctors or health care workers in the United States who are willing or able to take off a month or two to go work in Liberia treating patients with Ebola? Of course there are some, and we’re trying to rapidly get those people trained and mobilized. But it’s not a huge number.

MSNBC: People in the United States are presumably worried about Ebola out of proportion to the actual risk. I wonder if you could put in perspective the threat we face from Ebola, compared to say, Enterovirus, which has been linked to four deaths in the U.S. How do those viruses compare to other pandemic threats?

BAUSCH: We often confuse the lethality of a virus with its transmissibility. Ebola is no doubt a lethal, dangerous virus, but there are many viruses that are much more readily transmitted than Ebola. Many viruses that don’t strike fear into the hearts of people, like Chickenpox, are much more infectious.

If you look at the two pandemics we’ve had in this century, starting with the SARS pandemic in 2002 and the H1N1 pandemic in 2009, those viruses were much easier to catch, but had much lower case fatality – about 8% in the case of the SARS virus, and less than 1% for H1N1. So people often confuse those things. Unless you are really in a setting where you’re a healthcare worker or a family member caring for a person who is sick with Ebola virus, you probably couldn’t get Ebola if you wanted to.

There are other pandemics that are more likely to happen, but that isn't to diminish what’s going on. This is a global disaster, a humanitarian crisis to which we need to respond, recognizing that we’re all interconnected through our humanity but also our economics. Though we don’t necessarily feel it, we’re dependent on West Africa, and they’re certainly dependent on us.