Search This Blog

Wednesday, August 20, 2014


There is a person in California who is in isolation for possible Ebola virus infection. He is exhibiting signs of viral infection, and he was recently somewhere in West Africa.

Death by epidemic was one of my favorite obsessions back in the 90s, along with financial melt-down and future dystopia. Such themes have also been frequent in films and books, and they form the " lasciate ogni speranza voi ch'entrate " embellishing the entrance to the cavern of the future for our generation.
("Abandon all hope, you who enter here"; from Dante's Inferno)

Science is on top of things, but the scientific process is not terribly robust, it being but a human endeavor and prone to human failings, like viable smallpox cultures hidden away in a desk for 40 years.

Although we are told that Ebola cannot be transmitted through the air ( as an aerosol, a colloid composed of fine particles and liquids in gas - in this case, the gas is air ).

I believe that exactly means that Ebola cannot be transmitted through the air between human beings, and not that it is entirely impossible that the Ebola virus can be in some sort of infectious aerosol.
Studies have been done:

Are we *sure* Ebola isn’t airborne?
Posted by Tara C. Smith on August 3, 2014

Let me back up. The paper in question was an experimental study done in the wake of the 2008 finding of the Reston Ebola virus in pigs and a previous study looking at the Zaire virus in pigs. In the air transmission study, they inoculated pigs with Ebola and examined transmission to macaques (who were not in direct contact with the infected pigs). They did find aerosolized Ebola in air samples, and some of the macaques did come down with symptoms of Ebola. So, it looked like pigs could spread Ebola through the air, which is something that had already been suggested by the epidemiology of the 2008 pig Ebola outbreak. It’s always nice when experimental data matches up with that observed during a real-life occurrence of the virus.

*However*, the kicker was not that Ebola is transmitted by air in human outbreaks, but rather that there may be something unique about pig physiology that allows them to generate more infectious aerosols as a general rule–so though aerosols aren’t a transmission route between primates (including humans, as well as non-human primates used experimentally), pigs may be a bigger threat as far as aerosols. Thus, this may be important for transmission of swine influenza and other viruses as well as Ebola.
(underline emphasis mine)

If air-borne transmission is heavily dependent upon the virus-carrying aerosols, there should be investigation into the nature of pig aerosols and how they differ from aerosols produced by humans (such as the aerosols produced by sneezing). However, the question of how pig aerosols significantly differ from human aerosols has not received a lot of attention.

At the beginning of this month, it seems that orders went out to burn the bodies of Ebola victims in Western Africa.
Heat may produce aerosols, such as a laboratory situation where a hot loop is introduced into a culture. A body which is not uniformly subjected to virus killing heat may produce an aerosol, I should think.
What the nature of those aerosols are is anybody's guess.

And, by the by, the Ebola virus is transmitted by contact with bodily fluids, such as are contained in spit, blood, urine, feces, etc.
The old belief that aerosols are created when one flushes the toilet are actually true; in experiments where toilet bowls were swabbed with some bacterium, measurable amounts of bacteriua-containing aerosols were detected after the first few flushes.


No comments: