How to Prevent the Spread of Norovirus in Restaurants

Posted On: July 30, 2020

Norovirus is not the contagious disease du jour.

But long before you had to take precautions for COVID-19 in the restaurant industry, you were taking food safety measures to prevent disease transmission.

They're as important now as ever. Regardless of what else is going around, it's never a good time to give your customers food poisoning.

And just as every fact we learn about coronavirus helps us fight it better, understanding the biology of norovirus – the leading cause of foodborne illness – can help you prevent an outbreak in your kitchen.

What Is Norovirus?

Norovirus is often referred to as the "stomach flu." You'd think that means it's related to influenza, but it's not.

They do have certain things in common that make it easy to mix them up. They're both caused by viruses. They're both highly contagious. Both can cause fever, headaches, and body aches.

They both mutate quickly, causing multiple strains to circulate at the same time. Some strains are more severe than others, and immunity to one strain doesn't stop you from catching another.

And while it's possible to catch either year-round, outbreaks of both spike between November and April.

But influenza's signature symptoms are respiratory (like a sore throat, cough, and congestion), whereas norovirus is called a stomach bug for a reason. It causes "acute gastroenteritis," which includes symptoms like:

Diarrhea
Vomiting
Nausea
Stomach pain

While you catch "the flu" from being coughed or sneezed on, the "stomach flu" largely spreads through contaminated food. Norovirus accounts for:

58% of foodborne illness outbreaks
19-21 million cases of acute gastroenteritis per year
$2 billion a year in lost productivity and healthcare expenses

Norovirus also comes on and disappears faster than influenza. Most people recover on their own after 1 to 3 miserable days.

It can hit harder with the young, the elderly, and people with other health conditions. Dehydration can land them in the hospital.

In severe cases, it can kill.

Why Is Norovirus So Common and Contagious?

It's so common because norovirus is extremely easy to transmit and extremely hard to kill. It's:

Highly Contagious. Sick people shed billions of norovirus particles while they're sick. It takes as few as 18 viral particles to infect someone else. To put that in perspective, you can infect 1,000 people with the amount of norovirus that fits on the head of a pin.
Abrupt Onset. Symptoms can come on quickly. If an infected person vomits in a public place, they can expose many people at once. It only takes a droplet.
Heat Resistant. Norovirus can survive temperatures up to 145°F, so quick steaming processes don't kill it. This is why shellfish is a common source of norovirus outbreaks, along with fresh fruit and leafy greens.
Freeze Resistant. It can also survive in the freezer. (This is an understatement—one study found that norovirus stayed infectious after 120 days at -112°F.)
Environmentally Hardy. Norovirus can survive in the environment (think: countertops and cooking utensils) for up to 2 weeks.
Resistant to Disinfectants. Cleaning counters and utensils with soap and water only spread the norovirus around. Hand sanitizer leaves a contagious load behind. In other words, precautions you might take for COVID-19 will not protect against norovirus. In fact, many common disinfectants are also ineffective.

Put all of that together, and the best way to prevent a norovirus outbreak is to avoid contact with other people while you're contagious. But this presents some unique challenges to the food service industry.

How Can Restaurants Prevent Norovirus Outbreaks?

According to the Centers for Disease Control and Prevention (CDC), food service workers cause 70% of reported norovirus outbreaks by coming to work while contagious.

That means if you manage a food service operation, you bear a lot of responsibility in preventing this illness.

The following policies can do a lot to curb norovirus within your business.

Strict Time Off for Employees During and After a Stomach Bug

You're most contagious with norovirus while you're sick and for 24-48 hours afterward. That means you should keep your workers out of your establishment for 3 to 5 days starting at the first sign of symptoms.

According to the CDC, 1 in 5 food service workers admit they've gone to work with vomiting and/or diarrhea. Factors that keep them from staying home include:

Fear of losing their job
Guilt over leaving coworkers in the lurch
Inability to meet their financial burdens without those hours

As a manager, your policies directly impact their decision to put your customers at risk. You can increase compliance by:

Making it clear employees won't be punished for calling in sick with these symptoms
Putting robust coverage procedures in place
Offering financial incentives for staying home during the contagious period

The last is obviously the biggest ask for a cash-strapped business, but it's worth considering. It's possible to enforce a norovirus no-work policy without financial incentives, but you risk employees hiding their illness in the name of paying rent.

Hand Hygiene Practices

Keeping symptomatic employees at home is well and good, but the contagious phase can begin before symptoms present and continue for up to 2 weeks after symptoms stop.

That means every employee needs to take precautions against contaminating food, including:

Proper Handwashing. A 2008 study by the Food and Drug Administration (FDA) found that food service employees only practice proper handwashing 25% of the time they should. Train all employees on the FDA's recommended handwashing procedures and reinforce their recommendations.
Not Touching Ready-to-Eat Food with Bare Hands. According to the CDC, 54% of outbreaks caused by infected workers came from touching ready-to-serve foods with their bare hands. That includes sandwiches, baked goods, cooked dishes, and raw fruits or vegetables that have already been washed for serving. The FDA recommends a combination of hand washing and single-use gloves to prevent illness. Your employees should be trained on their glove-use recommendations.

These measures are especially critical the 2 weeks after a stomach flu episode.

Time and Temperature Controls

You should practice Time and Temperature Controls for Safety (TCS) all the time with at-risk foods.

But norovirus, as we mentioned, is especially heat resistant. If you're concerned about norovirus contamination in your kitchen or on your staff, you need to exceed 145°F rather than the recommended 135°.

You should always cook shellfish to 145°F, regardless of a previous norovirus outbreak, because shellfish can be contaminated in the water before it's harvested.

Produce Washing

Fruits and vegetables can also be contaminated with norovirus in the field, and since they're often served raw, that's a problem.

The FDA's produce cleaning recommendations include:

Proper handwashing before and after produce prep
Choose produce that isn't bruised or damaged (or cut away those areas before preparation)
Discard the outermost leaves of lettuce or cabbage heads
Rinse produce before peeling to avoid utensil contamination
Use plain water and mechanical action to clean your produce, not soap. For firm produce, use a clean vegetable brush. For other produce, rub gently with your hands while rinsing.
Rub produce dry afterward with a clean paper towel. This helps remove the remaining pathogens.

Sanitize Surfaces and Utensils Regularly

Routinely wipe down kitchen surfaces and utensils with products capable of killing norovirus.

The CDC recommends using a chlorine bleach solution made by mixing 5-25 tablespoons of household bleach (5-8%) per gallon of water.

Alternatively, the Environmental Protection Agency (EPA) publishes a list of commercial products that are norovirus effective.

Food Hygiene Training for Staff

Prevent a norovirus outbreak requires compliance from every staff member. They can't comply with something they don't understand, so it's important to provide training on the proper procedures and why they matter.

In many jurisdictions, the legal requirements for food safety training are easy to meet: one manager needs to be certified in food safety. The law assumes that managers will accurately train everyone else.

But there's a lot of evidence that this doesn't work. That leaves your business at risk.

Staff-wide training is more effective. Specifically, you should invest in:

Multiple managers with Food Safety Certification. Ideally, you should schedule one certified manager to be on the premises at all times. The FDA reports that food safety increases when compliance is actively monitored by a manager. Focus on positions like Kitchen Manager, where trained vigilance will do the most good.
Food Handler Training for everyone else. Managers don't have the time or skill to teach food safety properly. Food handler courses are designed for front- and back-of-house staff. They focus on the information that entry-level staff needs to protect your customers from food poisoning. And they work.

Bottom Line

Year after year, restaurants remain the most common source of foodborne illness outbreaks. The hit to your reputation and bottom line can be devastating. Luckily, it's preventable with education and the enforcement of food safety practices.

Online courses are by far the most affordable and convenient solution for the food service industry. We're an ANSI-accredited provider with over 20 years of online training experience. We offer both individual courses and whole-business solutions to keep your workforce compliant and your customers happy.