As 2026 begins, norovirus — often dubbed the “stomach bug” or “stomach flu” — is circulating widely, leaving many people feeling miserable with sudden vomiting and diarrhea. But what exactly is norovirus, how does it spread, and what can you do to protect yourself and others? Experts in infectious disease and public health have clear guidance to separate myths from facts, describe common symptoms, and explain practical prevention and care.
What Is Norovirus?
Norovirus is a group of related viruses that cause acute gastroenteritis — inflammation of the stomach and intestines. While often called the “stomach flu,” it is not caused by influenza viruses and is unrelated to respiratory flu illnesses.
It is the leading cause of vomiting, diarrhea, and foodborne illness in the United States and affects people of all ages.
Why Is Norovirus So Contagious?
Norovirus spreads extremely easily. A key reason is its very low infectious dose — it takes only a few dozen virus particles to make a person sick. Infected individuals can release billions of viral particles in stool and vomit, contaminating hands, surfaces, food, and water.
People remain contagious from the time symptoms begin until several days after they recover, and in some cases the virus can be shed in stool for up to two weeks after symptoms end.
Norovirus can survive on surfaces for days to weeks and is incredibly hardy, resisting many common disinfectants and surviving temperatures that would kill many other viruses.
Symptoms of Norovirus Infection
Symptoms typically begin 12–48 hours after exposure and include:
- Sudden vomiting
- Watery diarrhea
- Stomach cramps
- Nausea
- Low-grade fever
- Body aches and fatigue
Most healthy people recover within 1–3 days, but dehydration from fluid loss can be a concern. Symptoms that are severe, persistent, or accompanied by signs of dehydration (such as dizziness, dry mouth, or reduced urination) warrant medical attention.
Myths vs. Facts
There’s a lot of misinformation about norovirus. For example:
- Myth: Norovirus is the same as food poisoning.
Fact: Food poisoning is typically caused by bacteria, while norovirus is a viral infection — though both can cause vomiting and diarrhea. - Myth: Hand sanitizer can prevent norovirus.
Fact: Alcohol-based sanitizers are not effective at killing norovirus. Proper handwashing with soap and water is the gold standard for prevention.
How Norovirus Spreads
Norovirus transmission commonly occurs through:
- Direct contact with an infected person
- Contaminated food or water
- Touching contaminated surfaces then touching your mouth
- Environments with close person-to-person interaction such as schools, daycares, nursing homes, and cruise ships
Prevention and Care
Because there is no specific antiviral treatment or vaccine, preventing norovirus comes down to hygiene and supportive care:
Prevention Tips:
- Wash hands thoroughly with soap and water, especially after using the bathroom and before preparing or eating food.
- Disinfect surfaces with a bleach-based cleaner or EPA-approved product effective against norovirus.
- Avoid preparing food for others while you are sick and for at least 48 hours after symptoms stop.
- Clean contaminated laundry separately in hot water.
Managing Symptoms at Home:
- Stay hydrated with clear fluids or oral rehydration solutions.
- Rest until symptoms subside.
- Introduce bland foods gradually once nausea improves.
- Seek medical help for dehydration, persistent symptoms, or if vulnerable populations (young children, the elderly, pregnant people) are affected.
Final Thought
Norovirus is unpleasant and highly contagious, but with proper preventive measures and supportive care, most people recover quickly without complications. Being mindful of hygiene — especially handwashing — remains the best defense against this pervasive stomach bug.
