Inactivation of norovirus on dry copper alloy surfaces

PLoS One. 2013 Sep 9;8(9):e75017. doi: 10.1371/journal.pone.0075017. eCollection 2013.

Abstract

Noroviruses (family Caliciviridae) are the primary cause of viral gastroenteritis worldwide. The virus is highly infectious and touching contaminated surfaces can contribute to infection spread. Although the virus was identified over 40 years ago the lack of methods to assess infectivity has hampered the study of the human pathogen. Recently the murine virus, MNV-1, has successfully been used as a close surrogate. Copper alloys have previously been shown to be effective antimicrobial surfaces against a range of bacteria and fungi. We now report rapid inactivation of murine norovirus on alloys, containing over 60% copper, at room temperature but no reduction of infectivity on stainless steel dry surfaces in simulated wet fomite and dry touch contamination. The rate of inactivation was initially very rapid and proportional to copper content of alloy tested. Viral inactivation was not as rapid on brass as previously observed for bacteria but copper-nickel alloy was very effective. The use of chelators and quenchers of reactive oxygen species (ROS) determined that Cu(II) and especially Cu(I) ions are still the primary effectors of toxicity but quenching superoxide and hydroxyl radicals did not confer protection. This suggests Fenton generation of ROS is not important for the inactivation mechanism. One of the targets of copper toxicity was the viral genome and a reduced copy number of the gene for a viral encoded protein, VPg (viral-protein-genome-linked), which is essential for infectivity, was observed following contact with copper and brass dry surfaces. The use of antimicrobial surfaces containing copper in high risk closed environments such as cruise ships and care facilities could help to reduce the spread of this highly infectious and costly pathogen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alloys / chemistry*
  • Animals
  • Antiviral Agents / chemistry*
  • Cell Line
  • Chelating Agents / chemistry
  • Copper / chemistry*
  • Decontamination
  • Disinfectants
  • Fomites / virology
  • Food Contamination / prevention & control
  • Food Microbiology
  • Linear Models
  • Macrophages / cytology
  • Mice
  • Monocytes / cytology
  • Nickel / chemistry*
  • Norovirus / physiology*
  • Reactive Oxygen Species
  • Stainless Steel
  • Surface Properties
  • Temperature
  • Virus Inactivation*
  • Zinc / chemistry

Substances

  • Alloys
  • Antiviral Agents
  • Chelating Agents
  • Disinfectants
  • Reactive Oxygen Species
  • nickel copper alloy
  • Stainless Steel
  • brass
  • Copper
  • Nickel
  • Zinc

Grants and funding

The research was funded by the Copper Development Association, NY and the International Copper Association, NY. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.