12/15/2025
Q) Help! How can I stop the spread of a “stomach flu” caused by Norovirus?
A) To stop the spread of Norovirus: reach for bleach, wash your hands, don’t share, close the lid, and stay home for two full days if possible. Noroviruses are the most common cause of “stomach bug” outbreaks (vomiting, diarrhea) in older kids and adults. They strike fast and hard, and are very contagious.
2025 UPDATE: With data through Nov. 21, 2025, Amanda Bidwell, scientific program manager for the WastewaterSCAN program (https://tinyurl.com/5s28mx99), said norovirus wastewater concentrations have increased nationwide by 69% since October (https://tinyurl.com/ybv7nhjd). You can have a look at wastewater data here (https://tinyurl.com/5n89dmw4).
(This post was updated by Those Nerdy Girls from the original published on December 22, 2024.)
🦠Norovirus is a prime suspect if you or your kid are experiencing sudden diarrhea, stomach pain and vomiting that last 1-3 days - but can’t be explained by too much birthday cake or trampoline time on a full stomach. Other symptoms include fever, headaches, fatigue, and muscle pain. If this sounds familiar, it’s best to get serious ASAP about stopping the spread.
🔎Whodunnit tip: To identify the likely source, count back 12-48 hours (median 33 hours), as this is the average length of time long from Norovirus exposure to explosive symptoms (aka “incubation period). If your kid starts puking Saturday night, they were probably exposed on Friday.
Note: For kids under age 5, Rotavirus is another possible culprit. Fortunately, Rotavirus infections are not nearly as common as they once were in many countries, thanks to routine immunizations. There is no vaccine for Norovirus
Top Tips for Stopping the Spread of Noroviruses
🪣Reach for bleach to clean surfaces and fabrics! Do it early and often.
Bleach is proven to kill Noroviruses, whereas many other disinfectants do NOT get the job done, including alcohol-based hand sanitizers and wipes (unless they are bleach-based). Wear gloves, use fresh bleach, diluted to an appropriate strength, and let the bleach soak in for a solid 5 minutes before scrubbing.
👉Use a bleach solution to swiftly to clean up all traces of vomit, and routinely clean high-touch areas, like doorknobs, light switches, and toilet and sink handles.
👉For dirty sheets and clothes, use hot water and detergent with bleach (½ cup). If bleach is not feasible, use an oxygenated detergent (look for “oxy”, “oxo”, “oxygen”).
👉For dishes and utensils, use a dishwasher if possible, and crank up the heat!
To make a 1:50 (1,000 ppm) cleaning solution of bleach and water: Add 20 ml of bleach to 1 liter of water (5 to 25 Tbsp of bleach [5% to 8%] per gallon of water) and mix together. Make sure you add the bleach solution to the water when preparing the solution, not vice versa. See links below for more info.
🫧Wash your hands! Use soap and water. Often. Thoroughly (20 seconds or more). This goes for everyone, not just the sick person!
To defeat Noroviruses, clean hands are imperative, and good old soap and water is your best bet. Norovirus often spreads through direct contact from touching contaminated surfaces, then touching our faces.
🚽Close the lid! The toilet is where the action is with Norovirus. If possible, let the sick person have their own bathroom.
When someone is infected with Norovirus, their f***s and a**s are teeming with viable virus for a week or longer. Even just a few dozen of these invisible particles can spread disease. Once you’ve seen a toilet plume - filled with nasty bugs - you’ll always remember to close the lid.
🛑Don’t share! Minimize contact with the sick person, and avoid shared objects.
Noroviruses spread through direct contact, including fabrics, toys, dishes, eating utensils and more. Do your best to minimize contact (which we know is really hard with little ones!).
🔥Pro Tip: Switch to paper towels instead of hand towels in shared bathrooms when someone is ill to avoid spreading germs.
🏠Stay home! Even if you feel better, waiting an extra day or two can spare others from hugging the toilet.
Public health agencies generally advise staying home for 24 to 48 hours *after symptoms have resolved* - and longer for people with weaker immune systems (including infants) and those who serve food or provide healthcare. Why ?The infectious risk is highest from symptom onset until 48 hours *after* symptoms resolve, which means you can spread it after you feel better. In fact, Noroviruses can usually be detected in f***s for at least a week, often longer.
⚠️Warning: Many Norovirus infections are asymptomatic, up to one third of cases! Asymptomatic carriers can also shed a lot of virus in their f***s. It’s best for the whole family to dial up precautions when there’s a stomach bug at home.
💬Communicate and educate! Sharing our stories and the science behind disease transmission is a win for communities.
Talking with family and friends about how viruses spread can help them understand and follow preventive actions. The information you share may cause someone to think twice before sending their kid to school or having friends over, shortly after a puke-a-thon. So go ahead, share this post!
Talking openly about sickness within your community can also help nip outbreaks in the bud. This Nerdy Girl recently had a child throw up out of the blue on a Saturday night. It turns out that at least 2 other kids from class were in the same boat, and each family assumed it was something they ate. By the time we connected the dots, another wave of kids in class were already sick.
Personal tips and tales from Those Nerdy Girls:
👉Do your best but be realistic. It’s virtually impossible to eliminate every viral particle, even if you follow every tip, let alone when you have little ones that need our cuddles. When the first case hits, think about what you can do to dial back demands, and get help, over the coming week in case others fall sick, including you!
👉Mind what you (and your kids) eat when there’s a bug going around. This Nerdy Girl got off easily when Noro took down her first kid hours after a bedtime banana snack. When the next kid fell ill three nights later, after eating a bowl of blueberries, things were much uglier!
👉Be prepared for a mess if you let your kid into bed with you after they vomit. They may soil your sheets in the next round - or pass it along so that your turn is next.
👉 This Nerdy Girl mom has found that her kids (age 7 and 11) are surprisingly understanding about the need for precautions that protect others when they are unwell - a silver lining from pandemic life. We also use analogies to help them understand how bugs spread - like imagining ink on your hands. I try to limit close contact with sick kids but give them lots of love in other ways, through words, special treats, and other caring acts. Of course, every family is unique and needs to find what works for their ages, needs, and priorities.
THE BOTTOM LINE
🤮If you or someone you love are hit by a stomach bug, we feel your pain and send our best wishes. To spare others from this horrible experience: reach for bleach, wash your hands, close the lid, don’t share, and stay home. Better yet, communicate and educate others so that we all bolster our germ fighting powers.
Last but not least - a tip for staying well when Noro hits home: stay hydrated! Slow and steady is your best bet as little sips are less likely to provoke more vomiting.
Related post from Those Nerdy Girls:
Close the lid! What is a toilet plume (https://tinyurl.com/a7n2d7ba)
Resources
Bleach dilution calculator (Foodsafe BC) (https://tinyurl.com/mvrjbhpr)
List of cleaning substances registered to kill Norovirus (EPA) (https://tinyurl.com/ycyxjktk)
Tips for cleaning your home when somebody has Norovirus (NoroCORE) (https://tinyurl.com/ym23nn3f)
Norovirus prevention (US CDC) (https://tinyurl.com/6wp5n4jk)
Norovirus guidelines for healthcare settings (US CDC) (https://tinyurl.com/3v797rmm)
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