The findings of the University of Ottawa and North Carolina State University research teams were published in the journal Applied and Environmental Microbiology and show that transmission of multiple enteric viruses can be reduced by newly synergistically formulated ethanol-based hand sanitizer.
The annual number of food-related infections in the US is an estimated 76 million, with viruses accounting for 79 per cent and human norovirus (HNV) causing 59 per cent of such cases, according to the study.
Norovirus, one of the most common causes of gastroenteritis, is highly contagious and can be spread through human contact; in one case, five norovirus outbreaks affecting several hundred people in Denmark in 2005 were traced to a single batch of contaminated frozen raspberries.
Hygienic food processing and handling can reduce the spread of the virus.
In addition to washing with soap and water, the US Center for Disease Control and Prevention (CDC) and the World Health Organisation (WHO) recommend the use of alcohol-based hand sanitizers in food handling environments for faster microbial kill and less dependence on running water.
According to the researchers, the effectiveness of ethanol alone to inactivate vegetative bacteria, fungi and enveloped viruses is well demonstrated but they claim that there remains a need for hand sanitizers which can inhibit a broad spectrum of nonenveloped viruses, including HNV.
The objective of the study was to compare a synergistic blend of ethanol, polyquaternium polymer and organic acid with a benchmark alcohol-based hand sanitizer in terms of their capacity for inhibition of animal and human viruses.
The scientists explained that an assessment of how well human noroviruses survive food processing is difficult because you can not grow them in culture and as a result most of the research done on HNV has been carried out using a surrogate virus that is a derivative of a cat pathogen, feline calicvirus (FCV); however its relevance as a surrogate for HNV has been questioned.
The team said that the recent in-vitro cultivation of murine norovirus type 1 (MNV-1) provides an alternative and more suitable surrogate than FCV and they incorporated it into their investigation as a result.
The research team said that they undertook suspension and fingerpad protocol assessments using the new sanitizer and the control.
In the suspension test, the new ethanol-based sanitizer showed reduced infectivity of human rotavirus (HRV), poliovirus type 1 (PV-1), and human norovirus (HNV) surrogates FCV and MNV-1 by greater than 3 log whereas the control alcohol-based sanitizer reduced only HRV by greater than 3 log and none of the additional viruses by greater than 1.2 log after the same exposure.
In the fingerpad experiments, the newly developed sanitizer produced a 2.48 log reduction of MNV-1 while the control product only produced a 0.91 log reduction.
“Based on these results, we conclude that this new ethanol-based hand sanitizer is a promising option for reducing the transmission of enteric viruses, including norovirus, by food handlers and care providers,” said the team.
Source: Applied and Environmental Microbiology 74.16: 5047-5052 Published online ahead of print"Improved inactivation of nonenveloped enteric viruses and their surrogates by a novel alcohol-based hand sanitizer,"Authors: D.R. Macinga, S.A. Sattar, L. Jaykus, J.W. Arbogast