An analysis released Thursday by a team of prominent researchers claims that airborne transmission of Ebola is "very likely," but only through limited mechanisms such as sneezing or coughing on someone.
The question of whether the Ebola virus could spread through the air, or if it could mutate to become an airborne virus, has been a hotly debated topic among health experts, with most believing that the virus cannot.
But the new scientific analysis published in mBio, a journal of the American Society of Microbiology, calls those beliefs into question.
"It is very likely that at least some degree of Ebola virus transmission currently occurs via infectious aerosols generated from the gastrointestinal tract, the respiratory tract, or medical procedures," the scientists wrote, "although this has been difficult to definitively demonstrate or rule out, since those exposed to infectious aerosols also are most likely to be in close proximity to, and in direct contact with, an infected case."
Lead author of the paper, Michael T. Osterholm, an epidemiologist at the Center for Infectious Disease Research and Policy at the University of Minnesota, published an op-ed article in The New York Times last September raising the possibility that Ebola could be spread through the air, but was dismissed by many, according to The Washington Post.
Experts have long claimed that Ebola is transmitted only by contact with infected body fluids like blood, vomit or feces.
In December 2014, Politifact even included the airborne Ebola claim on its "2014 Lie of the Year" list.
"There was almost a rush to ensure the public that we knew a lot more than we did," Osterholm said in an interview Wednesday night. "But we're saying you can't rule out respiratory transmission."
Other authors include Pierre Formentry of the World Health Organization's pandemic response unit, Gary P. Kobinger of Canada's Public Health Agency, Clarence J. Peters, of the Galvestone National Laboratory at the University of Texas Medical Branch, and a number of other experts from around the world.
The paper acknowledges that airborne transmission of Ebola is still unproven, and affirms that the virus most commonly spreads through bodily fluids, but provides a few pieces of evidence suggesting that the virus also likely spreads through air in a limited fashion.
For example, the authors point to the fact that the virus has been found on the outside of face masks worn by health care workers caring for Ebola victims, also noting that the virus has been passed between animals via respiration.
Ebola can also infect certain cells of the respiratory tract, like epithelial cells, which line body cavities, the authors said, and macrophages, a type of white blood cell that engulfs and digests pathogens.
The paper says that breathing, sneezing, coughing and even talking can eject droplets of fluid from the respiratory tract which travel short distances and, if they land on a mucous membrane, could most likely cause an infection.
Aerosols expelled by infected persons could also be temporarily suspended in mid-air and inhaled by others, the authors say.
