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Why Ebola is very unlikely to go airborne

Not likely to spread Ebola.
Not likely to spread Ebola.
Media for Medical/Getty Images

Ebola is not currently an airborne disease. You can't catch Ebola by sitting across the room from someone who has it. You can only catch Ebola from coming into direct contact with the bodily fluids of someone who has the disease and is showing symptoms.

(One caveat: If someone with Ebola symptoms sneezes or coughs and the saliva or mucus hits your eyes, nose, or mouth, that can transmit the disease, but this is rare, and it's mainly a concern for health workers. It's also not what people mean by "airborne.")

Back in September, however, an op-ed by Michael Osterholm in The New York Times raised a disturbing possibility — what if the Ebola epidemic in West Africa goes on long enough and the virus keeps mutating? Could Ebola somehow become airborne then? And wouldn't that allow the disease to spread even faster around the world? More recently, Dr. Oz raised the specter of airborne Ebola on The Today Show.

This is a scary scenario. But fortunately for the world, most infectious disease experts remain very skeptical that Ebola will ever become airborne. "This is way down on the list of possible futures for Ebola and in all probability will never happen," explained Ian Jones, a virologist with the University of Reading, back in September.

'We've never seen a human virus change the way it is transmitted'

But why are experts so confident Ebola won't become airborne? It's worth reading this long post by Vincent Racaniello, a virologist at the College of Physicians and Surgeons at Columbia University.

He goes into detail about how viruses mutate, but here's his bottom line: "We have been studying viruses for over 100 years, and we've never seen a human virus change the way it is transmitted":

When it comes to viruses, it is always difficult to predict what they can or cannot do. It is instructive, however, to see what viruses have done in the past, and use that information to guide our thinking. Therefore we can ask: has any human virus ever changed its mode of transmission?

The answer is no. We have been studying viruses for over 100 years, and we've never seen a human virus change the way it is transmitted.

HIV-1 has infected millions of humans since the early 1900s. It is still transmitted among humans by introduction of the virus into the body by sex, contaminated needles, or during childbirth.

Hepatitis C virus has infected millions of humans since its discovery in the 1980s. It is still transmitted among humans by introduction of the virus into the body by contaminated needles, blood, and during birth.

There is no reason to believe that Ebola virus is any different from any of the viruses that infect humans and have not changed the way that they are spread.

I am fully aware that we can never rule out what a virus might or might not do. But the likelihood that Ebola virus will go airborne is so remote that we should not use it to frighten people. We need to focus on stopping the epidemic, which in itself is a huge job.

This jibes with what Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, told the Senate in mid-September: "Very, very rarely does [a virus] completely change the way it's transmitted."

Fauci noted that viruses do mutate a lot, in ways that might make the disease more virulent or a little bit more efficient at spreading. That's why researchers are currently trying to monitor the mutations. But with all the dire things to worry about with Ebola, he said, the prospect of the disease going airborne is not "something I would put at the very top of the radar screen."

Further reading: For more on the science of Ebola transmission, check out this previous post by Susannah Locke. She notes that, yes, some pigs infected with Ebola may be able to transmit the disease by coughing and sneezing large droplets. But there's a huge caveat here: Ebola affects pigs in a completely different manner than it does humans (in pigs, Ebola shows up as an infection of the lungs; in humans, it mainly targets the liver).