Norovirus is the most common cause of acute nonbacterial gastroenteritis in the U.S. The winter months, or as some people call it, the cold and flu season, is a time of year to be especially aware of this potential threat to your customers and your business.

According to the FDA Food Code, your employees are required to report to you any illness they may have that is transmissible through food.

Norovirus is one of those illnesses. Several years ago, two other family members, three family friends and I struggled through a bout of norovirus.  

All six of us became violently ill 36 hours from food consumption to the onset of symptoms—a blasting headache, severe cramping and abdominal discomfort, dizziness, nausea, muscle soreness, projectile vomiting and diarrhea. The sickness was disorienting, incapacitating and uncontrollable.

If this had happened to my elderly parents, someone pregnant, very young or immune-system compromised, it could have been fatal.  

Our experience was the result of a food handler not properly washing his hands after using the bathroom. Fecal material was transferred from the food handler’s hands to a ready-to-eat food product that all six of us consumed. This type of contamination is typically referred to as the fecal-oral route.  

Studies have found that food handlers are capable of transferring an infective dose of norovirus onto seven different clean surfaces. The amount of virus transferred to each successive surface will be reduced, but because the infective dose is low, the first several surfaces contaminated will be capable of infecting up to 14 people. Because we are dealing with a virus, which is not really living or dead, it’s capable of remaining on a doorknob or a handrail for a very long time.

In light of these facts, you can see how norovirus led to the nightmares we’ve read about on cruise ships. If someone on a ship touches a contaminated handrail and does not wash their hands before eating, they will ingest the virus by the fecal-oral route.

Once ingested, the norovirus will invade a healthy cell in the individual’s body and start its work. Until the norovirus on that handrail is completely removed by either additional hand contact or disinfection, it will continue to infect people.

This leads to another special characteristic of norovirus. Normal sanitizers and disinfectants do not kill or deactivate it. If an infective dose of norovirus is sitting on a handrail and a member of the cleanup crew wipes down the surface with a typical quat-based sanitizer or even a chlorine-based sanitizer at the approved concentration level of 200 ppm, other potentially infectious pathogens may be removed, but not the norovirus. Normal sanitizers barely faze this nasty agent of illness.

It’s important that an employee who has or has had norovirus notify you of their illness because the individual can shed infective virus cells long after they are symptom free. If you are informed, you can monitor, restrict or exclude the individual.

It’s also been established that norovirus does not need to be transferred from fecal contaminated fingertips to food or a doorknob. Two of the symptoms described above, projectile vomiting and diarrhea, can be airborne transmitted.This illness can come on so quickly, it’s possible for a customer or employee to become sick in your dining area, restroom or back of the house.

The first line of defense is to have a solid food safety management program with the appropriate prerequisite programs in place. If you have a structured program in operation, you’ll be better prepared to deal with an extreme crisis if it should occur.  

The prerequisite programs includes personal hygiene and hand washing. Proper hand washing with soap and water is capable of physically removing norovirus from contaminated hands. Though existing alcohol-based sanitizers have been shown to be ineffective against norovirus, Purell has recently introduced a hand sanitizer that has proven to be effective in deactivating the virus. Nevertheless, when preparing food, never substitute the use of hand sanitizer for hand washing.
If you are concerned with properly cleaning and sanitizing surfaces and you believe you are dealing with norovirus, the first step should be to consult with the appropriate regulatory authority. It will be able to help you develop a plan and advise you on materials to use. For example, hypochlorite (bleach) at a concentration level well above 200 ppm can be used to deactivate norovirus, but you would want to have additional guidance because it could create separate hazards within your facility.  

For the most part, existing sanitizers and disinfectants have proven to be ineffective in removing the norovirus from surfaces. However, we know that the act of physically cleaning and rigorously scrubbing surfaces with approved detergents and sanitizers can help.

Hal King, PhD, and his team at Chick-fil-A, who are responsible for food and product safety, have put together an extraordinary program for “cleaning body fluids” in their foodservice facilities. While the program is not meant specifically to deal with norovirus, it’s thorough enough and broad enough to address the threat of the virus.  

The key is to make procedures as simple and as effective as possible following a body-fluid release incident. The pictures and descriptions above illustrate this approach.