Norovirus: Symptoms and Treatment
The highly contagious norovirus can tear through cruise ships, classrooms, and other crowded spaces, leaving vomiting, diarrhea, and stomach cramps in its wake.
It spreads easily through food and drink and can have a big impact on people's health. The CDC estimates that noroviruses are responsible for more than half of all food-borne disease outbreaks each year.
What Are Noroviruses?
Worldwide, noroviruses are thought to be the most common cause of acute gastroenteritis (diarrhea and vomiting illness).
On average, noroviruses cause 19 million to 21 million cases of acute gastroenteritis in the U.S. per year, according to the CDC. The norovirus was originally called the Norwalk virus, after the town of Norwalk, OH, where the first confirmed outbreak happened in 1972.
Because there are many different types of noroviruses, exposure to one type may not protect you from other types.
While they can strike year round, they’re more common in the winter, says Edward Gaydos, DO, a pediatrician at the Cleveland Clinic. (Norovirus is also called the “winter vomiting bug.”)
“You’re miserable for 1 to 3 days,” says Gaydos. “It’s usually an abrupt onset and a quick recovery. It’s a nuisance, but it’s not something to panic about. Most people will do fine with it.”
Noroviruses are sometimes called food poisoning, because they can be transmitted through food that's been contaminated with the virus. They aren't always the result of food contamination, though.
Is Norovirus the Stomach Flu?
Norovirus is not related to flu. Flu is an infection of the respiratory system that causes fever, chills, aches, and pains. In fact, there’s no such thing as stomach flu, and it’s a term that Gaydos encourages patients to avoid. The confusion that it causes can have serious consequences.
“Sometimes people don’t want the flu shot because they say they’ve already had a stomach flu,” says Gaydos. “I try not to use that term."
What Causes Infection With Noroviruses?
People become infected with noroviruses when they eat or drink contaminated foods and beverages. Raw or undercooked oysters and raw fruits and vegetables have been implicated in some outbreaks. You can also get infected if you touch an object or surface that has been infected with the virus and then touch your nose, mouth, or eyes.