Infection Control Marketing

Ebola is Viable Through Air Transmission

"Ebola virus particles" by Thomas W. Geisbert, Boston University School of Medicine - PLoS Pathogens, November 2008 direct link to the image description page doi:10.1371/journal.ppat.1000225. Licensed under Creative Commons Attribution 2.5 via Wikimedia Commons

Most all fevered people are infected with virus (or bacteria) and most if not all of the contagion in their breath is aerosolized, including virus and bacteria.  In fact this is also true of all excretions albeit blood, sweat or tears. Poop and vomit no less.  That’s simply because the fever itself is the way the body fights such an epidemic or infestation.  And like most bodily infections, all bodily fluids contain the infesting contagion.  In short, fevered people’s infectious agents in their virus or bacteria are aerosolized or airborne.

Now in fairness to the Center of Disease Control’s (CDC) claiming Ebola is not airborne, the CDC meant that they observed a lack of airborne activity through epidemiology (study of the spread of the disease) in the equatorial Africa, namely the tropics.  There the characteristics of disease spread often resembles the southern United States indoor air near perfectly in the summer months.  But since fall and winter sees exponential drops in indoor moisture into which sick people exhale, the CDC had no epidemiologic study to make this claim.  Moreover the CDC’s study on non-human primates demonstrate clearly the airborne nature of the disease spread of Ebola.  The CDC claim then gets minimized to say that “airborne human to transmission has never been demonstrated”.  Now as of October 27th, the CDC model includes a 3 foot droplet spread possibility which the CDC claims by definition is not airborne.  And to that from the CDC, I disagree respectfully again.

Ebola behaves similarly to influenza in the tropics so far as disease spreading is concerned.  In tropics like Viet Nam, Singapore, subtropical Hong Kong, summer in the US, it moves around slowly before winter.  Winter is when it goes airborne in the United States.  But why?  The difference in US locations and our varying seasons is the change of indoor moisture levels, while the tropics and subtropics remain constant.  In the tropics even with air-conditioning there, Relative Humidity (RH) is around 40-60% (RH).  In non-air-conditioned they are upwards of 100%.  It is in these higher indoor and outdoor humidity levels where viral diseases spread mostly by bodily fluids (fomite) and droplet spread.

Patient 0 at Presbyterian in Dallas on October 4th-5th was isolated with only attendants in his space.  Unlike Patient 0 at Prince of Wales Hospital in Hong Kong on March 4th-5th 2003.  Both days are significant and similar between those hospitals over 10 years apart.  Both had highly infected and thereby highly infectious index patients (patients 0).  And on those days, I hypothesize below that 100+ people were infected with SARs in Hong Kong and 2 nurses in Dallas.  What made them similar?  One climactic event.  A large drop in indoor moisture with a low moisture end point.  In Hong Kong it was about 35%.  In Dallas it was about 25%.  So why would a drop in moisture matter and why would dryness create disease spread, especially when the days in Hong Kong and Dallas were such beautiful days outdoors.  The answer is found in gas physics.

This story is about rapid crystallization of human excrete in indoor dry air and conversely the pickling of virus and bacteria in moister indoor air.  Picture the body for what it is in physics: a ~100F dew point source of hydrated excrete.  Take exhalation.  When we exhale mucus droplets we are releasing droplets of mostly water, a little salt and a protein called mucin.  When we are febrile we are contagious so the mucus contains often concentrations of the contagion causing the fever – viral or bacteria. The more febrile, the likelihood of more contagion.

Therefore when a sick person exhales 100F dew point droplets into a normal humid indoor environment, say 50% RH, the mucus droplet will evaporate slowly.  This slow process creates a saltier and saltier concentration corroding the virus protein envelope, deactivating it for good.  For once you can now look at humidity as a kind of antiseptic.

Conversely when the fevered person releases breathe into drier air, the droplet evaporates rapidly.  The drier the air, the lower the dew point, the more rapid the vaporization. It is rapid vaporization that the virus prefers.  That is when the droplet vaporizes so rapidly that the virus never brines because the salt crystalizes and ejects from the now dry droplet.  Then to look at the remaining droplet is to see a hairball-like structure, invisible to the eye, porous, still some warmth so floating upward from its remaining specific heat, around head level or higher where it came from and then following air currents, if any.

Influenza virus tests confirm this salt crystallization as increasing greatly the viability and infectiousness in dry air.  Recent studies at VPI, Mayo and Wake Forest reinforce the idea that dryness increases viral viability. These studies have curves testing viability showing increased infectiousness from 10 to 100x as you go to RH from 50% down to 20% RH.

So yes, it is likely that Ebola just as influenza, SARs and MERs have been shown to be airborne in dry air – also aerosolizes viably in dry air.  The principal is the same for all such contagion.  There are certainly limiting factors to various contagion and loads that are required to cause infectiousness but Ebola appears to be a virus that perform similarly.

Also, the rapid drop on October 4th in Dallas could have also caused the nurses to have added susceptibility (in drying out their respiratory’ s mucus lining) making both Patient 0’s mucus droplets more concentrated and the nurses susceptibility to them increased.  The answer to such indescribable danger is simple. Humidify deliberately but smartly for a safe healing and working environment.

1. Maintain RH at a midpoint of 50% using WelloControl
2. Permit people to self-screen using WelloStation for temperature screening
3. Know the indoor moisture conditions with WelloWatch


Additional Resources

?p=3524