JAN 10, 2017 8:25 AM PST

Just add salt!

WRITTEN BY: Kerry Evans

Surgical masks were originally designed to be used during, well, surgery. They physically protect the wearer from all the hazards of surgery - blood and body fluids, for example. The problem is that many people don surgical masks during widescale disease outbreaks - think SARS or MERS.

Students wear masks during a SARS outbreak. South China Morning Post

Traditional surgical masks can trap aerosol droplets containing infectious viruses, but that’s about it. The trapped virus is still infectious, and people handling the mask can still be infected. On the other hand, N95 respirators can effectively trap viruses and prevent their spread. However, users must be trained, and the respirators must be fitted by a professional to work effectively - all of which are roadblocks during an epidemic event.

Engineers at the University of Alberta in Edmonton saw a solution - just add salt! Hyo-Jick Choi and colleagues have been working to develop oral vaccines. The problem with vaccines in a pill form is that when liquids in the vaccine are dried to form a pill, crystals form that deactivate the virus in the vaccine. The virus particles are literally stabbed (for lack of a better term) by the crystals, damaging and deactivating them.

Choi decided to make lemonade from his oral vaccine lemons - he added salt to the surgical mask filters. When a respiratory droplet that contains viruses lands on the salty filter, the droplet absorbs salt. As the liquid evaporates, the salt crystallizes, destroying the viruses.

Next, they set to testing the modified filters in the lab. They exposed mice to a lethal dose of aerosolized H1N1 influenza virus - either through a bare filter or the salt-treated filter (I like to imagine the mice wearing tiny surgical masks). The mice exposed to H1N1 through the bare filter rapidly succumbed to disease, dying within 10 days. However, mice exposed to the virus through a salt-treated filter showed 100% survival and significantly lower lung viral titers (compared to controls).

The group then tested how well the salt-treated filters deactivated viruses. Virus adsorbed onto bare filters lost only 8% hemagglutination (HA) activity. In contrast, virus adsorbed onto the salt-treated filters lost virtually all HA activity within 5 minutes! When the researchers looked at the viruses under an electron microscope, they found that the salt-treated filters physically damaged the virus particles.

Because table salt is essentially harmless, and surgical masks are already a safe, approved product, Choi and his colleagues hope to make this new technology available to the public very soon. Almost 8,000 Canadians were hospitalized with the flu during the 2014-2015 season, and close to 600 people died. Hopefully this simple, salt-treated surgical mask can decrease these numbers.

Source: Nature Scientific Reports, University of Alberta, Wikipedia

About the Author
  • Kerry received a doctorate in microbiology from the University of Arkansas for Medical Sciences.
You May Also Like
APR 05, 2021
Microbiology
Salmonella Outbreaks Linked to Bird Feeders, Pet Turtles
APR 05, 2021
Salmonella Outbreaks Linked to Bird Feeders, Pet Turtles
Many types of bacteria often live harmlessly in and on animals and humans, but some bacteria pose a threat. Salmonella b ...
APR 15, 2021
Clinical & Molecular DX
A Portable Ebola Detector, 1000x More Sensitive Than Lab-Based Tests
APR 15, 2021
A Portable Ebola Detector, 1000x More Sensitive Than Lab-Based Tests
Duke University scientists have created a highly sensitive Ebola virus portable diagnostic device, 1000 times more sensi ...
APR 13, 2021
Microbiology
Learning How TORCH Pathogens Cause Brain Malformations
APR 13, 2021
Learning How TORCH Pathogens Cause Brain Malformations
The term TORCH pathogens refers to a group of viruses including Toxoplasma gondii, Rubella, Herpes Simplex Viruses 1 and ...
APR 19, 2021
Microbiology
Small Differences Enable Some Microbes To Persist in the Gut
APR 19, 2021
Small Differences Enable Some Microbes To Persist in the Gut
The world is full of microbes that have colonized nearly every environment including the human body. The vast majority o ...
APR 26, 2021
Microbiology
Ocean Bacteria Can Add Carbon to the Atmosphere
APR 26, 2021
Ocean Bacteria Can Add Carbon to the Atmosphere
Scientists are noting that rock-dissolving microbes in the ocean may be contributing to climate change and should be tak ...
JUN 20, 2021
Cell & Molecular Biology
What Triggers a Sneeze?
JUN 20, 2021
What Triggers a Sneeze?
For most of us, a whiff of pepper or tickle in the nose will trigger a sneeze. The action can rapidly expel whatever mig ...
Loading Comments...