#15,421
It's not exactly a new idea, although for the first time - thanks to a study published today in Nature Communications - we appear to have laboratory evidence that influenza A viruses (and probably others) can be transmitted via airborne or `aerosolized fomites'.
Fomites are any surface or object that can become contaminated with viral, fungal, or bacterial pathogens and that can then later contaminate - and possibly infect - anyone who touches, handles, or ingests them.
While the authors of today's study describe their work as venturing into `seldom considered' territory, this is actually a topic we've touched on with some regularity over the years. The science of all of this even has a name; aerobiology – the study of how bacteria, fungal spores, pollen and even viruses can be passively transported in the air.
- In 2010 (see Viruses Blowin’ In The Wind?) we saw a report in the journal Environmental Health Perspectives, that suggested that it was possible for H5N1 (or any Influenza A virus) to be transported across long (hundreds of kilometers) distances in the air, although viability was unknown.
- In 2012's Barnstorming Avian Flu Viruses? we looked at a study in the Journal of Infectious Diseases called Genetic data provide evidence for wind-mediated transmission of highly pathogenic avian influenza that found patterns that suggested farm-to-farm spread of the 2003 H7N7 in the Netherlands due to the prevailing wind.
- Another study of the same outbreak, Modelling the Wind-Borne Spread of Highly Pathogenic Avian Influenza Virus between Farms (PloS One 2012), found that wind borne transmission could have accounted for up to 24% of the transmission over distances up to 25 km.
The following month (May, 2015), in CIDRAP: H5N2 Roundup & Detection In Environmental Air Samples, we looked at air sampling conducted by the University of Minnesota around infected poultry farms that found evidence of airborne virus particles.
(Note: Audio link no longer appears live
We've seen numerous other instances where the `dust’ (desiccated chicken manure, feathers, etc.) from chicken farms or live markets has been strongly suspected of spreading bird flu – at least for distances of a few hundred yards.
Most of the evidence we've seen to date, however, has been anecdotal, or circumstantial.
Today's study - using guinea pigs - provides the first direct experimental evidence that viable Influenza A viruses can be carried through the air by dust, fibers, and other `non-respiratory' particles.
This open access study is lengthy, and quite detailed, and so you'll want to follow the link to read it in its entirety. I've only posted the abstract below.
Published: 18 August 2020Sima Asadi, Nassima Gaaloul ben Hnia, Ramya S. Barre, Anthony S. Wexler, William D. Ristenpart & Nicole M. BouvierNature Communications volume 11, Article number: 4062 (2020)AbstractInfluenza viruses are presumed, but not conclusively known, to spread among humans by several possible routes. We provide evidence of a mode of transmission seldom considered for influenza: airborne virus transport on microscopic particles called “aerosolized fomites.”
In the guinea pig model of influenza virus transmission, we show that the airborne particulates produced by infected animals are mainly non-respiratory in origin. Surprisingly, we find that an uninfected, virus-immune guinea pig whose body is contaminated with influenza virus can transmit the virus through the air to a susceptible partner in a separate cage. We further demonstrate that aerosolized fomites can be generated from inanimate objects, such as by manually rubbing a paper tissue contaminated with influenza virus.
Our data suggest that aerosolized fomites may contribute to influenza virus transmission in animal models of human influenza, if not among humans themselves, with important but understudied implications for public health.
