Norovirus: A Highly Contagious Stomach Bug

March 22, 2023

Blonde woman complaining of pain in stomach side to doctor

Norovirus is a common cause of the “stomach flu”—not to be confused with the flu itself, says Dr. Melanie Dubois, a specialist in pediatric infectious diseases and an Assistant Professor in Pediatric Infectious Diseases at Weill Cornell Medicine.

Norovirus infections in the New York Metropolitan Area appear to be high this year, Dr. Dubois says. The virus tends to peak between November and April, so we’re still in norovirus season, with an increase in emergency room visits for vomiting and diarrhea in the area.

The virus mainly causes vomiting and watery diarrhea, but in some patients, it may also cause nausea, fever, body aches and stomach pain. Norovirus infection comes on quickly—just 1 to 2 days after exposure—and its symptoms typically ease within 2 to 3 days.

How contagious is norovirus?

Norovirus is very contagious. You can catch it by:

coming into direct contact with an infected person (via vomit or stool)
consuming contaminated food or water
touching contaminated surfaces at home, on public transportation or in restaurants

And you can continue to spread it to others for 2 weeks or more after your symptoms clear.

“Just a few virus particles are enough to cause infection,” says Dr. Dubois. “It’s also a very ‘stable’ virus, meaning it can stay on surfaces for weeks.”

According to the Centers for Disease Control (CDC), you can get norovirus many times in your life, as there are many different types of noroviruses. Infection with one type may not protect you against other types, so don’t be surprised if your child comes down with another norovirus-driven stomach bug next season.

Who is most vulnerable to catching norovirus?

People can catch the virus at any age, but young children and older adults are particularly susceptible and at risk for severe disease, along with people taking immunosuppressive medications.

What is the best way to treat the symptoms of norovirus?

There are no prescription medications available for the treatment of norovirus. That’s why Dr. Dubois urges parents to provide what doctors call “supportive care”: namely, fluids and rest. “Kids can become dehydrated with this virus,” she says, “so give your child plenty of fluids, including water and electrolyte-containing beverages.”

More about dehydration

Be aware that successive rounds of vomiting and diarrhea can easily cause dehydration, a potentially dangerous condition if prolonged. Symptoms of dehydration include:

decrease in urination
dry mouth and throat
dizziness, especially on standing up from a sitting or lying position

Should you or your child become dehydrated, get in touch with your primary care physician or pediatrician, who may decide to have you admitted to the hospital for emergency care.

How can we protect ourselves from norovirus?

Wash your hands often. As with some viruses, the hallmark of norovirus prevention is handwashing with soap and water. Note that hand sanitizer won’t kill norovirus—remember what Dr. Dubois said about its “stability”?—making handwashing even more important for prevention.

Wash all fruits and vegetables.
Use bleach-containing products to kill the virus on surfaces.
Stay home if you’re sick to protect others.

How can I keep my home norovirus-free?

The CDC warns us not to prepare food for others when we’re sick and for at least 2 days after our symptoms clear up.

To keep surfaces clean, routinely clean and sanitize kitchen utensils, counters and other surfaces before preparing food. Use a chlorine bleach solution or bleach-containing product.

When doing laundry, wear disposable gloves and wash all soiled items with detergent and hot water at the maximum cycle length; then dry them at the highest heat setting.

Norovirus in the New York Metropolitan Area

For several reasons, norovirus infections in and around the city have been difficult to track. Due to its short course, parents don’t tend to report or seek medical care for it, and they may not even be aware that norovirus is the culprit when their child gets the “stomach flu.” There’s also limited lab testing and less monitoring of the virus overall.

However, higher-than-usual levels of vomiting and diarrhea point toward norovirus as a possible cause, plus emergency room visits for these telltale symptoms are up.

Dr. Dubois says, “Most children will recover from the illness, but we must be on guard to prevent its spread in homes, schools and communities, particularly to protect the most vulnerable among us.”