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 Fish recognize their prey by electric colors
13.11.2018 | Rheinische Friedrich-Wilhelms-Universität Bonn

nachricht The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection
13.11.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

Im Focus: Coping with errors in the quantum age

Physicists at ETH Zurich demonstrate how errors that occur during the manipulation of quantum system can be monitored and corrected on the fly

The field of quantum computation has seen tremendous progress in recent years. Bit by bit, quantum devices start to challenge conventional computers, at least...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

The dawn of a new era for genebanks - molecular characterisation of an entire genebank collection

13.11.2018 | Life Sciences

Fish recognize their prey by electric colors

13.11.2018 | Life Sciences

Ultrasound Connects

13.11.2018 | Awards Funding

VideoLinks
Science & Research
Overview of more VideoLinks >>>