While people often associate norovirus with cruise ships, did you know that, according to the CDC, 99% of norovirus outbreaks occur on land? Here are a few places particularly susceptible to norovirus:

• Restaurants and food service venues

• Schools and daycares

• Hospitals and healthcare centers

• Long-term care and residential facilities

Why? Because norovirus is highly contagious. It can spread quickly in group settings through direct contact with an infected person particularly during winter months. Many individuals also contract it through contaminated food, water and environmental surfaces. And the virus can linger for weeks, since it’s not easily destroyed by many institutional cleaning products.

Is norovirus present in your facility? If you suspect an outbreak, the only way to know for certain is to test. Here are a few testing basics to help you prepare.

When to Test

The short answer is the somewhat obvious one: when people are getting sick. The actual criteria for what that means can vary by industry and even by organization. For example, one daycare center defines it this way: An outbreak of norovirus infection is suspected when more than two students or staff have symptoms. For food services, the U.S. Food and Drug Administration has minimum requirements for food employees who are symptomatic. The CDC website is a good resource for norovirus information and prevention, particular for food services and healthcare facilities.

Regardless of industry, it’s recommended you take action swiftly, testing as close as possible to when the incident occurred, or an outbreak is suspected.

What to Test

Surfaces that are more likely to be contaminated include the following:

• Restroom surfaces including toilets, sinks and faucets

• Food preparation areas such as counters, coolers, food traps, floor mats, ice machines and equipment

• High touch surfaces like tables, chairs, phones, floors, toys, doorknobs, light switches and elevator buttons

• Areas where ill employees have worked

• Areas where ill employees or customers may have vomited or had loose stools

How to Test

Here are a few established best practices for collecting norovirus samples for testing:  

1. Dress in clean clothing, including sterile, non-latex gloves.

2. Sample from the cleanest to less clean areas, changing gloves in each area.

3. Swab sample area using three strokes: horizontal, vertical and diagonal. Do not swab a surface area larger than 700 cm².

4. Place swab in a tube and tighten cap securely.

5. Label

6. Store and transport samples to the laboratory in an insulated cooler within 24-48 hours of collection.

For more on norovirus testing, watch this video. 

Recommended Testing Supplies

EnviroMax® (dry) and EnviroMax Plus® (pre-moistened) 6” Sterile Round Macrofoam Norovirus Detection Swab & Collection Tube

SKU#: 25-88060 PF UW DRY

SKU#: 25-88060 PF UW

Designed for surface sampling, these sterile collection-sampling kits are used for the detection of human norovirus on environmental surfaces. They conform to a newly developed CDC protocol that helps determine the level of environmental contamination during outbreaks.

Cleaning and Disinfecting

Use products that are EPA approved for use against norovirus. Chlorine bleach is often a go-to cleaner for disinfecting non-porous surfaces. Phenolic-based disinfectants can be effective too but often at concentrations higher than manufacturers’ recommendations. It’s important to note that quaternary ammonium compounds, which are often used for sanitizing food preparation surfaces, countertops and floors are not effective against norovirus.

The Best Defense Is a Strong Offense

From unhappy customers to potential lost revenue from an outbreak, it’s best to take any possible step to avoid an outbreak. Here are a few basic rules of thumb:

• Food handlers with symptoms such as diarrhea or vomiting should not work until at least 72 hours after their symptoms have stopped.

• Other facility workers with symptoms should not return until they are symptom-free for 48 hours.

• For residential environments, symptomatic customers/patrons should be isolated from the general population to limit exposure.

• Frequent hand washing is the best way to avoid the spread of most illnesses including norovirus. Post signs and educate workers on effective hand-washing techniques.

• Staff should use gloves and masks when cleaning up contaminated surfaces, such as when vomiting occurs.

• Cancel or postpone group activities and limit interaction with non-essential workers and outsiders when norovirus is present.

A norovirus outbreak is always an unwelcome occurrence. By taking steps ahead of time, you’re better able to prevent, address, test and clean up when norovirus and other outbreaks strike.

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