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Beware the Ever-Present Norovirus

Beware the Ever-Present Norovirus

While not the most dangerousfood safety contaminant, norovirus is so common it is a constant risk.

Noroviruses, which include Norwalk-type viruses, are a group of common contaminants that cause gastroenteritis or “stomach-flu.” They are very common, and some experts suggest they might be responsible the vast majority of non-bacterial gastroenteritis incidents in the world.

A study of their characteristics and travel patterns leads a manager to realize that the likelihood of having a food safety incident caused by a norovirus is much higher than one from other contaminating organisms. The risk is in the network of touches that form an invisible path between restaurant and food prep surfaces, restroom surfaces and ready-to-eat food products.

The risk ramps up in direct proportion to the number of times ready-to-eat elements are touched, directly or indirectly. How many hands, bare or gloved, have touched the sandwich lettuce before it was deemed ready to serve? How many hands are involved in the assembly and serving of a sandwich? How many prep surfaces have been touched by how many hands along the way?

Thanks to a study at Emory University led by Dr. Christine Moe, we now know that norovirus can survive for up to 6 weeks on common restaurant surfaces. We also have learned that workers can shed norovirus for up to 4 weeks without showing any symptoms of infection.

We have also learned much about the behavior of noroviruses from case studies with cruise lines, where norovirus “epidemics” can easily erupt, and from the Centers for Disease Control, charged with performing cruise ship health inspections. This data suggests norovirus infections more commonly begin with the passengers than with the galley staff. But just as in a restaurant or institution, the blame almost always falls upon the foodservice provider.

A Three-Pronged Offensive

To minimize the potential for norovirus infections in a sustainable way, a three-pronged offensive must be established and maintained. Contamination control starts in the kitchen, but effective interventions in restroom and service areas are mandatory.

In this regard, the Model Food Code is not especially helpful. It is largely structured to help operators address environmental elements that can be easily inspected. But most noro-based risk is related to behavioral issues. Three well-known code “standards” for hand hygiene illustrate this point: “must have a handsink,” “ no-bare-hand contact” and that the surface standard of cleanliness is one that is “clean to sight and touch.”

A measured and monitored kitchen handwashing system is a core best practice. This makes it possible to set, implement and monitor handwashing standards, providing management with decision support information and process control.

These practices and standards are best implemented by the use of reliable equipment and supplies, efforts to minimize the touch factor and the creation of an attractive handwashing area that is convenient and welcoming to staff.

In addition to clearly-defined standards, you should implement systems to verify, monitor and document both compliance and their effectiveness. That includes tools and policies to manage and minimize the potential effects of ill employees and ill customers as well as careful assessments of food flows and the invisible pattern of hand-touches in the course of a facility's operation — including those of staff, suppliers and the public.

The “Headwaters” of Norovirus

An effective hand hygiene risk assessment moves next to an area shared by all, the restroom. This is the most common source of norovirus and usually the beginning of its trip through the restaurant, hand by hand.

It is an unhappy fact of life that everyone wants a clean restroom but that no one wants to clean a restroom. Some operators turn to service professionals; provided a reliable company and appropriate service frequencies are selected, this option definitely has a place. At the same time, it must be coordinated with on-site schedules to maintain the desired standard. Sudden calls from nature can instantly change a restroom environment, even if a good sanitation regimen is in place.

If you have ill people on the property, whether staff or customers, where do you frequently find them? In the restroom, of course, where serious symptoms may include diarrhea and vomiting, two of the most potentially dangerous sources of norovirus, hepatitus A and bacterial invaders.

While surface cleanliness standards are neither set nor monitored by the health department, that fact should by no means be considered a free pass. Operators should establish standards based on actual public health risks, not simply passing an inspection.

One of the newest weapons in the fight to reduce ill customer risk is the introduction of noro-effective hand sanitizers. These are Food Code compliant and now available commercially.

In the realm of nano-noroviruses, where particle size is very small, cleaning procedures must be verified by measures beyond sight and touch. Sending swabs to the laboratory is one way. ATP tests are another, and one we believe is very useful.

Because ATP (Adenosine TriPhosphate) is present in all animal, vegetable, bacteria, yeast and mold cells, a detection of it on hard surfaces indicates a high likelihood of contamination by one of these sources.

With a single-use swab and a hand held luminometer, staff can check a reading for ATP presence on surfaces in just 25 seconds. This verifying tool allows for immediate corrective action.

Noro's Perfect Storm

Conditions to trigger a perfect storm for norovirus outbreak are most likely to exist in shared public space where it is very easy to have indirect contact between healthy and unhealthy customers and staff. Poor hand hygiene by any single person in these groups, combined with infrequent, incomplete surface cleaning, raises the risk of norovirus illness and outbreaks.

While an ill customer, student or patient can be the source of an outbreak, this is rarely identified in an epidemiological probe. The pathogen dropped off by him or her, networked back to the kitchen and staff, will usually be considered a breakdown in an your foodservice safety system and expose an operation to the powerfull legal principle of Strict Liability: if you cause harm, you are liable.

In the second part of this article, we'll look at the steps you can take to implement an effective surface contamination assessment system and at ways you can implement one that will encourage buy-in from members of your staff.

Jim Mann is the founder and Executive Director of the Handwashing For Life Institute, dedicated to helping operators set and achieve safe hand hygiene levels. Jim can be reached at: [email protected] or, visit

For More Information…

You can obtain information on ATP testing at the following site:

You can view information on Norovirus sanitation research at the following site, which also offers downloadable posters:

You can view information on the Center for Disease Control (CDC) vessel sanitation program at:

You can obtain useful Q&A handouts on norovirus from this CDC website:

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