Airborne viruses can spread on dust, non-respiratory particles

Date:
August 18, 2020
Source:
University of California - Davis
Summary:
Influenza viruses can spread through the air on dust, fibers
and other microscopic particles, according to new research. The
findings have obvious implications for coronavirus transmission
as well as influenza.



FULL STORY ========================================================================== Influenza viruses can spread through the air on dust, fibers and other microscopic particles, according to new research from the University
of California, Davis and the Icahn School of Medicine at Mt. Sinai. The findings, with obvious implications for coronavirus transmission as well
as influenza, are published Aug. 18 in Nature Communications.


========================================================================== "It's really shocking to most virologists and epidemiologists that
airborne dust, rather than expiratory droplets, can carry influenza
virus capable of infecting animals," said Professor William Ristenpart
of the UC Davis Department of Chemical Engineering, who helped lead the research. "The implicit assumption is always that airborne transmission
occurs because of respiratory droplets emitted by coughing, sneezing, or talking. Transmission via dust opens up whole new areas of investigation
and has profound implications for how we interpret laboratory experiments
as well as epidemiological investigations of outbreaks." Fomites and
influenza virus Influenza virus is thought to spread by several different routes, including in droplets exhaled from the respiratory tract or on secondary objects such as door handles or used tissues. These secondary
objects are called fomites. Yet little is known about which routes are
the most important. The answer may be different for different strains of influenza virus or for other respiratory viruses, including coronaviruses
such as SARS-CoV2.

In the new study, UC Davis engineering graduate student Sima Asadi
and Ristenpart teamed up with virologists led by Dr. Nicole Bouvier at
Mt. Sinai to look at whether tiny, non-respiratory particles they call "aerosolized fomites" could carry influenza virus between guinea pigs.

Using an automated particle sizer to count airborne particles, they found
that uninfected guinea pigs give off spikes of up to 1,000 particles per
second as they move around the cage. Particles given off by the animals' breathing were at a constant, much lower rate.

Immune guinea pigs with influenza virus painted on their fur could
transmit the virus through the air to other, susceptible guinea pigs,
showing that the virus did not have to come directly from the respiratory
tract to be infectious.

Finally, the researchers tested whether microscopic fibers from an
inanimate object could carry infectious viruses. They treated paper facial tissues with influenza virus, let them dry out, then crumpled them in
front of the automated particle sizer. Crumpling the tissues released
up to 900 particles per second in a size range that could be inhaled,
they found. They were also able to infect cells from these particles
released from the virus-contaminated paper tissues.

The work was supported by a grant from the National Institute of Allergy
and Infectious Diseases of the National Institutes of Health.


========================================================================== Story Source: Materials provided by
University_of_California_-_Davis. Original written by Andy Fell. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Sima Asadi, Nassima Gaaloul ben Hnia, Ramya S. Barre, Anthony
S. Wexler,
William D. Ristenpart, Nicole M. Bouvier. Influenza A virus is
transmissible via aerosolized fomites. Nature Communications,
2020; 11 (1) DOI: 10.1038/s41467-020-17888-w ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200818094026.htm

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