Everything You Need To Know About The Ebola Virus Outbreak

If you've been paying attention to the news recently, you've probably heard that several countries in western Africa are currently contending with the world's deadliest Ebola outbreak. In developments that hit a bit closer to home, over the past week, three hospitals in New York City have isolated and tested patients suspected of potential Ebola infection, the most recent case at Mount Sinai Hospital in Manhattan making the news yesterday. The patients all presented with potential Ebola-like symptoms (such as fever, gastrointestinal distress, headache), and several of them had traveled recently in western African countries. Fortunately, the New York Times reports that, so far, no new Ebola cases have been confirmed in the United States. According to a press release from Mount Sinai, the CDC is conducting tests on a specimen from the patient, who is currently in isolation, but "stable and in good spirits." Experts expect that he will not test positive for the disease, and that the isolation treatment is due to an abundance of caution.
Nevertheless, the unsettling news of suspected Ebola patients in Manhattan comes during the same week that two American aid workers, both infected with the virus after treating Ebola patients at a missionary clinic in Liberia, are receiving treatment at Emory University in Atlanta, Georgia. The first aid worker, Dr. Kent Brantly, 33, arrived in Atlanta two days ago; the second, Nancy Writebol, 59, who works with the international aid group SIM USA, arrived via jet in Atlanta today, reports the Charlotte Observer.
In light of the recent developments, we reached out to two experts: Chris Basler, Ph.D., a virologist specializing in Ebola at the Icahn School of Medicine at Mount Sinai in New York City; and Tim Lahey, M.D., an infectious disease specialist and associate professor of both medicine and microbiology and immunology at Dartmouth’s Geisel School of Medicine. Here’s what they had to say. (Note: In some instances, their answers have been edited for length and clarity.)
WH: First things first. How is Ebola spread?
Dr. Basler:
All the available information is that it spreads from person to person through contact with bodily fluids from an infected individual. It doesn’t seem to spread by being in close proximity, or by casual contact. The recommendations are that you avoid contact with infected individuals’ blood, feces, or other bodily fluids.
Dr. Lahey:
Even sitting next to a person with Ebola is thought not to be enough to transmit the disease, you need contact with body fluids. If that person sneezes on you, or bleeds on you, or a lot of sweat gets on you, then there is risk of transmission because body fluids have transferred from one person to the other, but Ebola is not airborn. So it requires those visibly obvious things to happen for transmission to occur.
That’s also why Ebola doesn’t typically spread like wildfire through communities, because how many people do you have that kind of contact with?
WH: When you say “contact with body fluids,” what exactly does that mean? If the fluids get on your skin? Or do they have to go into a cut or a mucus membrane, like into your eyes or something?
Dr. Lahey:
That’s the big concern, is getting a splash to the eyes is the big thing you worry about. I actually have not seen specific data on whether someone with Ebola whose body fluids get on completely intact skin, compared to a wound. I haven’t seen that type of direct comparison. The precautions that the CDC gives out say that providers should use gowns regardless of whether they have a wound or not. The safe option is to presume that any contact with body fluids confers some risk of transmission. But I think we’d all be most worried about contact that involves mucus membranes like mouth or eyes.
WH: So it takes anywhere between two and 21 days from the time of exposure until you start seeing symptoms. Are you contagious during that time?
Dr. Lahey:
No, its generally believed that you’re not contagious until you start showing symptoms.
WH: I’m envisioning a scenario where someone sneezes on the subway and suddenly everyone who rides the 7 train (like I do) becomes infected.
Dr. Basler:
The idea that it can be spread on the subway by a sneeze is relatively unlikely.
Dr. Lahey:
It’s a difficult question to answer, because how do you put it? There is conceivable risk there, but the risk in reality is just incredibly small. What’s the likelihood that someone with Ebola is going to be sitting in a New York City subway? First, how many cases of Ebola are there? Around 900 in the world today. And then you say almost all of those cases, with the exception of the few cases we’ve heard about in Nigeria and the United States, are in Sierra Leone, Guinea, Liberia, where most of the people are not international jetsetters. These aren’t people who just hop on a plane easily. The vast majority of people infected with Ebola are very unlikely to leave their region.
So let’s say there is someone… an aid worker who was not known to have Ebola and traveled to the United States, when he was asymptomatic, and then later became symptomatic after arriving. That’s the person you should worry about. British Airways is no longer flying to a couple of those countries to minimize that risk.
In any case, if someone like that was to become symptomatic and sick with Ebola and for whatever crazy reason was also not telling people or seeking help, and was also out on the subway, then… I guess it would be possible to transmit on the subway, via throwing up or sneezing. Those are conceivable risks. How likely? Hard to say. It’s conceivable. But all these things have to line up perfectly for it to be possible. And then on top of that, you'd have to have direct contact with his body fluids. [Editor's note: So if he sneezes on one end of the car, you'll be perfectly fine if you're not in his immediate proximity.]
Let me put it this way: There are way more common infections that we’re much more likely to be exposed to that are much greater cause for concern.
Or another way: We all worry about the serial killer coming and killing us, but in actuality the real risks in our lives are the trampolines in our backyards, swimming, sports, driving a car drunk… those are the things that actually kill us.
WH: If you have Ebola, is it in your saliva?
Dr. Lahey:
I think so, yes. Sweat, vomit, semen, breast milk, saliva… basically all bodily fluids.
WH: So it can be sexually transmitted also?
Dr. Basler:
There’s some evidence that there can be sexual transmission of the virus for a substantial period of time after at least some individuals have recovered from infection. So they clinically seem better, but they can still detect the virus in semen, and there’s at least one example of that.
Dr. Lahey:
There was a lab worker who was working with Ebola and got infected. So this was someone very amenable to being studied, and after he recovered from Ebola, which typically runs its course in a couple of weeks, he allowed researchers to perform studies on him. 61 days after initial infection or initial symptoms, he still had detectable Ebola in semen.
WH: So he was clinically “recovered,” but it was still detectable in his semen.
Dr. Lahey:
Yes. If you’re lucky enough to survive Ebola, celebrate with a condom.
WH: How long does it take for someone to clinically “recover” from the virus?
Dr. Lahey:
Couple weeks. Usually the easy way to remember it is on average it takes 2 weeks from exposure to develop symptoms, and from the time you develop symptoms, death will occur within a couple of weeks, or you’ll survive. Something like 40 percent of people survive.
WH: What’s the actual fatality rate? I’ve heard between 60 and 90 percent. Is that accurate?
Dr. Lahey:
I suspect the death rates we’re hearing quoted are probably not as applicable in the United States or Europe. The thing that causes death from Ebola is organ failure and sepsis, and that is very difficult to treat in Sierra Leone, for instance. But in the United States we have great ICU care, and are much better equipped to prevent that. If someone’s blood pressure is low, I can give them medicines to make it go higher. If their kidney is failing I can give them dialysis until their kidneys heal.
The next question of course is, well, what is the number? And nobody knows.
WH: So the way Ebola actually kills you is through organ failure… not the bleeding?
Dr. Basler:
Right. The bleeding doesn’t happen in all patients. Even in a significant number of fatal patients, you don’t see obvious signs of hemorrhage. So this Hollywood picture that you’re bleeding from every orifice is not particularly accurate. And even when there are manifestations of bleeding, it’s usually not copious. When people die of Ebola, blood loss is not a significant contributing factor.
Dr. Lahey:
That’s right, it’s not like the bleeding is so excessive that the patients become anemic or anything like that. It’s distressing and causes risk of transmission, but just like any infection, with Ebola virus, the blood pressure can fall, and that causes bad blood flow to the organs, like the kidney, causing kidney failure. It’s the same sort of thing that happens with staph infections.
WH: Does that mean it manifests the way a staph infection would?
Dr. Lahey:
In the end, it’s called sepsis. You have a profound inflammatory response to an infection, and you lose the ability to deliver the blood as a result. Sepsis from staph looks the same as sepsis from Ebola. As with any infection there are different grades of severity. You get a little touch of it, get a little extra fluid, that’s fine. Other people can be in the ICU for a long time. It kind of looks the same depending on the type of infection it is. Ebola stands out because of the rapidity with which it comes on, the frequency of death, the hemorrhagic symptoms.
But if you have a serious infection from any bug, the final common pathway is sepsis. That kind of looks the same with subtle variations from bug to bug to bug. But the whole low blood pressure and organ failure if untreated piece is really similar.
WH: I was listening to the radio this weekend and heard a bunch of people calling in to say that the American aid workers who contracted Ebola shouldn’t be allowed back in the country. What are your thoughts on that?
Dr. Basler:
The message from the CDC, which makes a lot of sense, is that any hospital in the United States is able to house and treat an Ebola virus patient safely. So there would be no reason to say that we shouldn’t bring back an American with the disease to treat them under optimal healthcare conditions. Within a hospital setting, the likelihood that a virus transmits to another individual is extremely low, so I think there’s very little to fear bringing these patients to the US.
WH: Ebola is a serious and terrifying public health issue in several countries in western Africa. If people start contracting the disease here in America, can we expect to see the same sort of situation?
Dr. Basler:
The big difference is that we have much better healthcare infrastructure and medical facilities. So if an individual is shown to be infected with Ebola virus, we could likely identify the people they’ve been in contact with relatively ease, and monitor them for signs of infection. Basically, the idea is that the virus is transmitted through close contact from the individual to other people, so if you can identify people who are potentially infected, the contacts of people who are known to have infection, then you can monitor them and isolate them so that they’re less likely to pass it to other individuals. That’s much easier to achieve in developed countries, as opposed to less developed countries.
WH: Many of the people contacting Ebola in Africa are doctors and aid workers. Why is that?
Dr. Basler:
I’m not there at the site of the outbreak, but I’d assume this reflects that these are people with frequent close contact with people who have frequent ongoing infections. I don’t know the circumstances in which all these healthcare professionals are interacting with the patients—whether they have the protective equipment available to them, or if they are well trained in protecting themselves—that would increase the likelihood of them getting infected.
The standard precautions that medical personnel take in the United States are likely sufficient to prevent them from becoming infected.
WH: What exactly are those precautions?
Dr. Lahey:
So if you had a patient who had suggestive symptoms and also came from the right area of the world, had exposure to a contact, then you have to wear special personal protective equipment that nearly all hospitals have. Those include face shields, masks, gloves and gowns. And one easy way to do this that you’ve seen in the news is you can use that full-body suit that includes the face shield and gloves, that’s one way to do it.
WH: Most American hospitals are equipped with this sort of protective gear?
Dr. Lahey:
Yeah. The really challenging part here in the United States isn’t typically about having the equipment that’s needed to protect caregivers, but having the thought process to think of using it. Symptoms of Ebola are sort of nonspecific in the beginning. You can get in the situation where you don’t think of it, you don’t take the precautions until you’ve already been exposed.
The Mount Sinai case was a good example where they heard some very general symptoms: fever, gastrointenstical symptoms, and if they hadn’t heard of the western African virology, they might not have thought anything of it. But because they knew what was going on in Guinea and Liberia and Sierra Leone, and they knew this patient had recently traveled in the area, they took precautions and put the patient in isolation, just in case.
WH: What happens to a patient who is put in isolation?
Dr. Lahey:
For the patient it’s relatively simple. Since Ebola is transmitted through body fluids, all the patient needs is to be in a private room with a door closed. That’s enough. Some things, like Tuberculosis, measles, chicken pox, you need to modify the airflow in the room and it’s more complicated. For Ebola, it’s not so easy to transmit, so it’s just a room with a door closed, and everyone who comes and sees them has to take those precautions, but the patient doesn’t have to do much.
WH: Is there anything else you think our readers should know?
Dr. Lahey:
I think the big thing to focus on is that people are naturally curious about this, it’s exotic, it’s new, it’s concerning, it’s getting a lot of media play. Knowing that there are in fact incredibly low odds of this causing any problems in the United States or developed world, and even if it does, the likely scope of this is going to be small. Which is why it’s important for us to keep our eye on the real global health ball: There are millions of people dying every year of things like malaria, HIV, diarrheal illnesses. I hope the coverage puts it in that context. Ebola is novel and unusual, but a very small impact compared to malaria, HIV, and TB.