The Volokh Conspiracy

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"Limited airborne transmission of Ebola is 'very likely,'" new study says


So reports The Washington Post (Lenny Bernstein at To Your Health):

A team of prominent researchers suggested Thursday that limited airborne transmission of the Ebola virus is "very likely," a hypothesis that could reignite the debate that started last fall after one of the scientists offered the same opinion.

"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, 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," the scientists wrote. Their peer-reviewed study was published in mBio, a journal of the American Society of Microbiology.

The study's lead author, Michael T. Osterholm, an epidemiologist at the Center for Infectious Disease Research and Policy at the University of Minnesota, touched off a small furor and was condemned by some experts last Sept. 11 when he raised the same possibility in an op-ed piece in the New York Times as concern over the spread of the deadly disease was increasing rapidly….

Osterholm's September opinion piece focused on the possibility that the virus could mutate and eventually become airborne, a theory that other experts widely dismissed as extremely unlikely. In contrast, Thursday's study examines the idea that minuscule droplets of body fluid containing the virus could hang in the air and be inhaled by others, providing an unrecognized, if minor, pathway for the virus.

This time Osterholm was joined in the paper by Gary P. Kobinger of Canada's Public Health Agency, Pierre Formenty of the World Health Organization's pandemic response unit and Clarence J. Peters, of the Galveston National Laboratory at the University of Texas Medical Branch, among many others.

The study, titled "Transmission of Ebola Viruses: What We Know and What We Do Not Know," takes pains to note that respiratory transmission of Ebola is unproven and that contact with infected body fluids is by far the most common way that the virus is passed from one person to another….

Asked why many more people who were near Ebola victims had not become infected, Osterholm said the Ebola virus may be much less contagious than other diseases spread by respiration, such as measles. He likened it to tuberculosis, which is more difficult to contract this way.