Airborne transmissibility by an Ebola sufferer's EXhalation of tiny particles originating in the lungs is not the same as airborne transmissibility via a new victim's INhalation of larger particles originating in an existing victim's esophagus and trachea.
The CIDRAP study linked in Black Agne's post No. 2160 properly states that the respective ranges of tiny Ebola-laden particles emitted from the lungs and larger particles originating in the esophagus and trachea form a continuum rather than a barrier. The larger particles mostly fall out of the air due to gravity about three feet from the emitting victim, but not all do. Some waft around for a fair distance, and can contaminate inert surfaces (fomites). Smaller particles hang around for longer and can go farther, which makes them really, really dangerous.
These “definitional issues” are of critical importance and absolutely worth fighting over.
The “droplet versus aerosol barrier” paradigm is obsolete with an ID50/LD50 at 10 viral particle transmission disease.
And if that medical paradigm is obsolete, so by extension is the idea of triage or separate PPE levels for separate hospital wards in cases of a suspected wide spread Ebola outbreak.
Everyone in the medical system dealing directly with the public will have to be in full BHL-4 PPE protocols 100% of the time with BHL-4 Terminal clean protocols that includes a documented positive chain of control from collection to cremation disposal of all PPE and personal clothing, hospital linens, other supplies, and especially bodies.
Otherwise we will see the public health-care system collapse from too many health care worker (HCW) Ebola casualties and ensuing HCW absenteeism. Followed by the public’s avoidance of the medical system as a proven place to get Ebola.
The “Droplet” versus “aerosol” definition is of critical importance to CDC/WHO/NIH messaging and preparations for Ebola here in America.
The public health authorities don't want to change to the new standards that the CIDRAP study represent for all the fear uncertainty and doubt it will raise with the public given the Ebola messaging they have used to control the public to date.
The “outside the frame of reference” reactions by the CDC/WHO/NIH bureaucracies to the ID50/LD50 at 10 viral particle transmission fomite threat is very much a part of that definitional issue fight.
The virus particles would have to survive. Ebola virus is very susceptible to drying out, which happens quickly in tiny particles.
That CIDRAP article (which is not a study) looks a lot like a PAPR advertisement to me. This isn't to say that PPE isn't important for patient care providers--it is--but it is important to understand context.