Food poisoning. Stomach flu. Stomach bug. The vomiting virus. Cruise ship disease.
We have a lot of affectionate nicknames for the leading cause of foodborne illness. But its proper name is Norovirus.
If you work in the restaurant industry, you don’t want to be on a first-name basis with the bug. To remain strangers, you need to understand what the norovirus is and how to prevent an outbreak in your kitchen.
What Is Norovirus?
Although we call norovirus the “stomach flu,” it’s not related to influenza.
It’s understandable to get them confused. They’re both caused by viruses. They’re both highly contagious. 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.
Both can cause fever, headaches, and body aches. But influenza causes respiratory symptoms—sore throat, cough, congestion. Norovirus causes “acute gastroenteritis,” with symptoms like:
- Stomach pain
While you catch the flu from being coughed or sneezed on, norovirus largely spreads through contaminated food. It accounts for:
- 19-21 million cases of acute gastroenteritis per year
- 58% of foodborne illness outbreaks
- $2 billion a year in lost productivity and healthcare expenses
Norovirus 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. And if they aren’t getting enough fluids, 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. While they’re sick, people shed billions of norovirus particles. 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 (i.e. countertops and cooking utensils) for up to 2 weeks.
- Resistant to Disinfectants. Cleaning counters and utensils with soap and water only spreads the norovirus around. Hand sanitizer leaves a contagious load behind. Many common disinfectants are ineffective against norovirus.
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 major responsibility in preventing this illness.
The following policies can do a lot to curb norovirus at 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 good, 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 detailed glove-use recommendations.
These measures are especially critical the two 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. Shellfish can be contaminated in the water before it’s harvested.
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/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 to help remove 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.
Alternately, the Environmental Protection Agency (EPA) publishes a list of commercial products that are norovirus effective.
Food Hygiene Training for Staff
Preventing a norovirus outbreak requires compliance from every staff member. They can’t comply with something they don’t understand, so you need 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 manager 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.
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 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.