Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New UNC experiments show very weak chlorine solutions can kill noroviruses

21.12.2005


Chlorine solutions much weaker than previously believed can still be used to kill more than 99 percent of noroviruses, the chief cause of outbreaks of gastrointestinal illness around the world, a new University of North Carolina at Chapel Hill study concludes.



Researchers presented their findings over the weekend at the 2005 International Conference on Antimicrobial Agents and Chemotherapy, which ends today (Dec. 19) in Washington, D.C. They discovered for the first time that dilute solutions of hypochlorous acid, or free chlorine, as low as 200 -- or even 20 -- milligrams per liter will completely inactivate noroviruses on surfaces such as stainless steel and ceramic tile.

Dr. Mark D. Sobsey, professor of environmental sciences and engineering at the UNC School of Public Health, and postdoctoral fellow Dr. Geunwoo Park conducted the research. They also found that the dilute chemical worked quickly -- in five minutes or less.


“This is good news since noroviruses are the leading cause of viral gastroenteritis,” said Sobsey, director of the school’s Environmental Health Microbiology Laboratories. “They have caused countless outbreaks of gastroenteritis in health-care facilities, schools, food establishments, hotels and resorts and on cruise ships.”

Decontamination of affected facilities can prove difficult since the viruses persist on environmental surfaces and are resistant to some widely used sanitizers, he said. And they are highly infectious even at low doses.

In their studies, the scientists dried a group II norovirus -- the predominant form circulating in the USA -- and a widely used indicator virus, bacteriophage MS2 infecting E. coli, on stainless steel and ceramic surfaces, Sobsey said. After treating those surfaces with a 200 milligrams per liter solution of hypochlorous acid for one minute, they tested them to learn how much virus remained. The viruses dropped 99.99 percent.

“Even a lower concentration of 20 milligrams per liter of hypochlorous acid reduced the viruses by 99.9 percent in five minutes,” he said. “Our results show that environmental surfaces can be readily decontaminated of noroviruses with dilute hypochlorous acid, which is the active ingredient of household bleaches like Chlorox.”

In practical terms, that means that household bleach can be diluted by a factor of 1,000 and still work, Sobsey said. In all likelihood, it would even disinfect noroviruses on hard surfaces if diluted by a factor of 10,000. At full strength, the bleach contains 50,000 to 60,000 milligrams per liter of chlorine.

“Previously, many people have diluted household bleach to one part in 10, which is still a strongly corrosive solution,” he said. “They often are reluctant to use at that strength since it can mar surfaces and make them look bad.”

Regularly disinfecting bathrooms, kitchens and other areas prone to harbor viruses and bacteria is important because outbreaks of gastrointestinal illness, which include nausea, vomiting and diarrhea, can kill people, especially if they are old or dehydrated, Sobsey said. While most otherwise healthy patients recover after a few days of discomfort even without treatment, noroviruses can continue to sicken others until facilities have been thoroughly sanitized with products proven to be effective.

In the research, Sobsey and Park generated hypochlorous acid from a dilute solution of salt using an electrolytic generator made by Sterilox Technologies. That company, which supported the research, manufactures on-site generators of room-temperature, high-level hypochlorous acid disinfectant for use in biomedical, food production, water treatment and other applications.

David Williamson | EurekAlert!
Further information:
http://www.unc.edu

More articles from Life Sciences:

nachricht Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Lying in a foreign language is easier

19.07.2018 | Social Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>