Study Finds Surface Sanitizers Inconsistent
Efficacy against norovirus can vary significantly according to formula and technique.
The study, recently published in the Journal of Applied and Environmental Microbiology, found that total formulation (the active ingredients and non-active ingredients) significantly impacts a surface sanitizer’s efficacy against human norovirus—the leading cause of foodborne illness in the United States.
Formula Makes a Difference
NC State researchers applied human norovirus and Tulane virus (a newer culturable surrogate virus with similarities to norovirus) to strips of Formica® (a laminate surface material commonly used in food service). They then tested the efficacy of four commercially available food contact surface sanitizers with different active ingredients (ethanol, bleach, quaternary ammonium, and a lactic acid and surfactant blend).
Only the alcohol-based (ethanol) sanitizer significantly reduced the amount of virus on the surfaces, while the others performed poorly.
“This research clearly shows all food contact surface sanitizers are not equal from a norovirus efficacy standpoint,” said Chip Manuel, Ph.D., GOJO food safety science advisor. “When considering products for an establishment, food safety professionals need to be confident in a product’s efficacy—especially for the hard-to-kill norovirus—so they should ask for data on product efficacy against this specific pathogen.”
The Good and Bad of Wiping Down
When testing the addition of a wiping-down step to the sanitation process, the study revealed both good and bad news. Using paper towels to wipe down the surface after application of any of the sanitizers provided removal of 95–99.9% of the virus. However, doing so introduced the possibility of cross-contamination, as the paper towels used with the three non-ethanol contained high concentrations of the virus after the wipe down. Furthermore, those same products still left residual virus on surfaces.
“This has implications for a facility’s norovirus clean-up plan,” Manuel said. “Paper towels used after cleaning up an incident should be handled very carefully, or cross-contamination could cause further illness.”
These findings come at the start of Food Safety Month and just ahead of peak norovirus season, which usually begins in October and lasts through April. Globally, norovirus sickens nearly 700 million people each year and costs an estimated US$64 billion a year, primarily through productivity loss, according to a 2016 study.
“Norovirus is the number one cause of foodborne illness in the United States, and this is partly because of how well this virus can persist on surfaces— it can survive for weeks,” Manuel said. “When it comes to controlling norovirus, selecting an effective surface sanitizer is only one piece of the puzzle—an establishment must rely on a total program approach. How good are employee hand hygiene practices? Are restrooms, touchpoints, or other high-risk surfaces disinfected on a daily basis? Are employees trained to respond to a bodily fluid situation when it happens? These are all aspects of a norovirus control program that are important to consider.”