Norovirus know-how: Tips to manage symptoms and contain the spread
February 5, 2025
Norovirus is a gastrointestinal virus that is as common as it is cunning. Infection spreads rapidly through contact with particles of an infected person’s vomit or feces. While it’s unsettling to think about, most people unwittingly touch or ingest waste particles several times a day that they pick up from common surfaces at work, school, the grocery store, church – anywhere people gather.
Infected people develop sudden, explosive vomiting and diarrhea that gets sprayed through the air when expelled by the body or when the toilet is flushed.
About 2,500 norovirus outbreaks are reported in the U.S. each year, each involving at least two people with lab-confirmed diagnoses. The current outbreak shows twice as many cases were reported the last week of December 2024 compared to peak reporting from 2021-2024. That number is almost certainly low, since reporting is inconsistent from state to state.
Norovirus spreads quickly in close quarters, such as during the winter months and in schools and daycares. And hundreds of cruise ship passengers are infected each year in a myriad of ways, from touching tainted buffet utensils to getting up close and personal in the conga line.
Though norovirus is far from rare, it has escaped medical understanding and effective treatment. New strains of the complex virus develop constantly.
Most people who get infected recover within 48 hours of symptom onset. But those who are immunocompromised, such as after an organ transplant, are at risk of developing chronic vomiting and diarrhea – sometimes lasting several years since there isn’t an effective antiviral treatment and/or vaccine to prevent norovirus infection.
“This virus is very crafty. Different strains have different growth requirements. And it hides – we don't even know which receptor in our gut it binds to.”
Infection worse when immunity is impaired
UT Southwestern infectious disease physician Pearlie Chong, M.D., has launched a study, funded by the National Institute of Allergy and Infectious Diseases, to understand the long-term impacts of norovirus infection in patients with impaired immunity. Dr. Chong and her research team’s goals are to better understand why some immunocompromised patients develop chronic and persistent symptoms while others do not by specifically looking at the role of gut microbiota in norovirus infections. In the long run, Dr. Chong hopes to help chronically infected individuals find relief and, in the process, translate those findings into an effective treatment that can potentially benefit everyone.
There’s no way to fully prevent norovirus infection – it only takes contact with a small amount of the virus to cause illness. The best way to reduce your risk is to be able to recognize norovirus symptoms and follow best practices to contain the spread.
Spot symptoms and know when to see a doctor
Norovirus symptoms come on quickly, causing your gut to rebel against nearly everything you eat or drink. While some may have a low-grade fever, the first sign is usually sudden onset vomiting, diarrhea, or both. Patients have said it feels like “everything is coming out of both ends,” with waves of nausea between episodes. Headaches and body aches become more pronounced as you lose fluids over 24-28 hours.
Most patients recover from norovirus at home within a few days. You probably won’t need to see a doctor if you can tolerate small amounts of water or other liquids. Try sipping these beverages to prevent dehydration:
- Plain water (the best choice)
- Vitamin-enhanced water
- Coconut water
- Flat ginger ale
- Pedialyte
Fruit-flavored popsicles and gelatins are also gentle on the stomach. Avoid dairy and minimize or dilute fruit juices and sports drinks while you’re symptomatic to reduce stomach upset.
If you can’t keep down water, the risk of dehydration and potentially fatal complications escalates. Seek medical care right away if you notice signs of dehydration.
- Decreased urination
- Dry mouth and throat
- Feelings of dizziness when standing up
- Crying with few or no tears
- Unusual sleepiness or fussiness
- Excessive fatigue
- Weakness
Though there is no effective treatment for norovirus, anti-nausea medication can help control symptoms. If you become dehydrated, you may need to get IV fluids in a medical setting and give your body a chance to rebuild its defenses.
Increased risks with low immunity
Norovirus can have serious long-term effects on people with weakened immune systems. This is because the gut microbiome helps shape the immune response, which is the process of finding and eliminating outside invaders such as viruses.
Patients who have an organ or stem cell transplant take medications to suppress their immune systems because the body sometimes sees their new organ or cells as a threat. These medications reduce the risk of organ rejection but also decrease the ability to fight real illness, leading to a higher risk of chronic norovirus infection. Patients with conditions such as cancer and HIV/AIDS may also be more susceptible to long-term symptoms.
Norovirus causes gastroenteritis, which is inflammation of the gut. Over time, that can lead to cell-level changes that cannot be detected without advanced testing and that make it tough for the gut microbiome to recover. This perpetuates chronic illness – some transplant recipients have endured up to nine years of chronic vomiting or diarrhea, which can be fatal.
While we can identify norovirus under a microscope, its underlying mechanisms remain elusive. In 2016, scientists discovered how to grow norovirus in the lab – a breakthrough that allowed researchers to investigate how the virus takes hold and grows in the gut.
Dr. Chong has received a prestigious National Institutes of Health career development grant to advance our understanding of the role of gut microbiota in human norovirus infections among transplant patients and to better characterize its impact on their already compromised immune system.
Related reading: Fecal transplants: Separating hype from reality
“This virus likes to set itself up for success. It doesn’t take much to make people sick, and the symptoms are explosive, allowing it to easily propagate itself."
5 tips to prevent norovirus from spreading
Follow these tips to help stop norovirus in its tracks.
Wash your hands with soap and water
Alcohol-based hand sanitizers are effective on most bacteria and some viruses but not norovirus. That’s because the alcohol breaks down the “envelope” of fat cells that protect the virus. Norovirus protects itself with a hard shell of protein called a capsid, which hand sanitizer can’t penetrate.
Handwashing, however, removes the germs from the hands. Wash your hands frequently with soap and water for at least 20 seconds each time:
- After using the toilet or changing diapers
- Before eating or preparing food
- Before giving yourself or someone else medicine
It’s especially important to wash your hands thoroughly when using a public restroom. Lidless toilets and shared surfaces are a primary pathway for norovirus to travel.
Isolate the sick family member
If anyone in your household has a sudden bout of vomiting or diarrhea, isolate them as soon as possible. Contain them to using one bathroom, if possible, and keep everyone else from using it. If the sick family member is a young child, you’re at risk to catch it by caring for them. Try to avoid touching your face, mouth, or eyes before you wash your hands. Encourage them to close the toilet lid when they flush.
Even when symptoms improve, the virus still sheds for a few days. Don’t send your child to daycare or school and don’t go to work or other events for at least 48 hours after you start feeling better.
Clean and disinfect shared surfaces
A diluted bleach solution – one part bleach to 10 parts water (1:10) – has proven to be the best solution to disinfect hard surfaces. Follow these steps:
- Wear disposable gloves
- Wipe down the area with paper towels
- Apply the bleach solution to every surface the patient may have touched, such as the toilet, faucets, light switches, and doorknobs
- Leave the bleach solution on the affected areas for at least 5 minutes
- Wipe down the surfaces with paper towels again
- Clean the area again with soap and hot water
- Dispose of the used gloves and paper towels in a sealed plastic bag
- Wash your hands with soap and water
You can disinfect hard plastic toys as well as high-touch surfaces such as railings and kitchen counters with this same bleach solution. Sterilize pacifiers in the dishwasher.
Handle laundry items carefully
A bout of norovirus usually means soiled bedding and clothing, especially with young children and older adults. Handle items that may have vomit or stool on them carefully, and keep them separated from other household laundry. To clean them:
- Wear disposable gloves
- Remove soiled clothes and bedding immediately
- Avoid shaking the soiled items
- Wash the items with detergent and hot water at the maximum available cycle length
- Machine dry at the highest heat setting
- Wash your hands with soap and water after handling each load
Avoid preparing, handling, or serving food
If you come down with norovirus, let someone take on the kitchen duties for at least two days after you start feeling better. Sharing food is another common transmission route for virus particles.
We all need to do our part to prevent a norovirus outbreak. Know the symptoms, stay isolated, and clean everything thoroughly. If anyone in your family is infected, notify schools and workplaces. Taking these steps can help all of us stay healthy and reduce the risk of serious illness.
To talk with an expert about norovirus infection, call 214-645-2800 or request an appointment online.
