Salt Spray Stops Germ Spread

Inhaling Himalayan Crystal Salt Brine appears to be very effective against respiratory infections.

Spray Could Stop Spread of Flu

by Maggie Fox, Tuesday, 30 November 2004

Some people exhale more germ-laden droplets than other people when they breathe, but a simple saline spray could prevent the germs from spreading, say a team of US and German researchers.

The team, led by Prof David Edwards from Harvard University, published their findings online ahead of print publication in the Proceedings of the National Academy of Sciences.

The study could provide a way to help control flu and other viral epidemics, such as Severe Acute Respiratory Syndrome (SARS), the researchers said.

The researchers studied the breath of 11 healthy male volunteers, giving them an oral saline spray and then measuring how many particles they released when coughing.

Some of the participants produced many more bioaerosols, small droplets of fluid exhaled from the lungs that may carry airborne pathogens, something also seen by investigators of the SARS outbreak that spread from China to cities around the world, killing 800 people.

That could mean that about half the population produce more than 98 percent of all disease-spreading droplets, the researchers said. Such “super-spreaders” could be responsible for several clusters of viral infection.

“We found a sharp demarcation between individuals who are ‘high’ and ‘low’ producers of bioaerosols,” said Edwards.

“Roughly half our subjects exhaled tens of bioaerosol particles per liter, while the other half exhaled thousands of these particles.”

Edwards said the number of exhaled particles varied dramatically over time and among subjects, ranging from a low of one particle per liter to a high of more than 10,000.

The researchers said that more droplets were spread when people breathed with their mouths open, as some people do habitually and which cold sufferers often must do, than when they coughed or sneezed.

Spray stops spread

The volunteers inhaled a salt spray for six minutes via a jet nebulizer, often used in the treatment of asthma. After the spray the high droplet producers’ output decreased by an average of 72% for up to six hours after the inhalation, the researchers said.

Using a cough machine designed to simulate normal human breathing, the researchers linked the saline spray to surface tension of fluid inside the lungs.

“Administration of nebulized saline to individuals with viral or bacterial illnesses could dramatically reduce spread of these pathogens without interfering with any other treatments,” Edwards said.

“This work could also point the way to new hygiene protocols in clinical settings as well as enclosed spaces.”

Viruses known to spread from humans and animals through breathing, sneezing, and coughing include measles, influenza, adenovirus, African swine fever virus, foot and mouth disease, chickenpox, infectious bronchitis virus and smallpox, among others, the researchers said.

Bacteria spread in airborne droplets include anthrax, Escherichia coli (E. coli) and tuberculosis.

The researchers noted much more study was needed before a saline spray device could be marketed to prevent the spread of diseases.

The study was funded by US biotechnology company Pulmatrix.

Author: Maggie Fox