Norovirus is commonly referred to as the stomach flu, but it’s not actually related to the influenza virus. This virus causes the stomach bug, bringing on gastrointestinal issues like diarrhea and vomiting, and it’s highly—yes, highly—contagious.
“Norovirus spreads quickly, often causing outbreaks during the winter months when people are indoors and in close contact,” says Christina Gagliardo, MD, director of Pediatric Infectious Diseases at Atlantic Health System.
“According to the CDC, cases have doubled from what we saw this time last year, possibly being driven by a new strain of the virus that continues to circulate and infect people.”
How is norovirus transmitted?
What makes norovirus so difficult to contain is its resistance to disinfectants and the ability to survive on surfaces and objects for days. It also easily contaminates food or water sources and spreads quickly from direct contact with an infected person or contaminated surface.
“Since norovirus is not killed by alcohol, hand hygiene should consist of washing hands well with soap and water and disinfecting contaminated surfaces with bleach,” says Dr. Gagliardo. “It takes very few viral particles to infect someone, so wash your hands well—and often.”
Signs and symptoms of norovirus
The signs of norovirus typically appear within 12 to 48 hours after exposure to the virus. These symptoms can range from mild to severe, and they usually last for one to three days:
- Nausea
- Vomiting
- Diarrhea
- Stomach pain and cramps
- Low-grade fever
- Headache
- Body aches
When to see a doctor
Though norovirus is rarely life-threatening, it can lead to dehydration in young children, older adults, and people with a weakened immune system. If persistent vomiting or diarrhea lasts beyond three days, or you notice severe dehydration such as dry mouth, dizziness, fatigue, or infrequent urination, it’s time to see a doctor.
“There are no medications to treat norovirus, so staying hydrated is the key,” says Dr. Gagliardo.
She explains the best way to replace lost fluids is to drink small sips of liquid and broth and to suck on ice cubes or frozen electrolyte pops.
“Most cases resolve on their own without any medical intervention,” says Dr. Gagliardo. “Besides rest, hydration, hand washing and cleaning surfaces with bleach, we advise staying at home to prevent spreading the virus to others until your symptoms resolve.”