Norovirus is spiking across the United States – Often called “stomach flu,” it isn’t a flu at all, but it is very contagious

Norovirus is a gastrointestinal illness that causes vomiting, diarrhea, and is highly contagious. Callista Images/Getty Images

Norovirus—an unpleasant and contagious stomach virus—is spreading in the United States, even closing a school in suburban Detroit for days last week. Data from the Centers for Disease Control and Prevention (CDC) shows that positive tests are at a seasonal high throughout the country, with the test positivity spikes in the Northeast (over 16 percent) the South (also over 16 percent positive), the West (over 12.5 percent), and a small dip from over 17 percent positive to under 15 in the Midwest. Currently, 14 states are reporting outbreaks of the virus and cases have also been rising in the United Kingdom and Canada.

Norovirus is commonly called the “stomach flu,” but is not related to the influenza virus. It generally causes nausea, diarrhea, vomiting, and stomach pain, and a mild fever and arches are also possible. It is usually spread through contaminated foods, surfaces, hands, or water and is also the annual leading cause of foodborne illness. The virus is extremely contagious and is often found on cruise ships, at schools, and in other environments where people share close quarters.

While norovirus can be contracted at any time of year, instances of the illness are most common from November to April in countries above the equator and between April and September in regions below the equator. One wildcard for 2023 is that changes in behavior due to the COVID-19 pandemic have interrupted natural cycles of many viruses. Since people have behaved differently since 2020, viruses do not travel the globe in their usual patterns, and population level (not individual immunity) is likely reduced, so we’re more susceptible to viruses and in different patterns.

Infectious disease specialist Dr. Daniel Kuritzkes from Brigham and Women’s Hospital in Boston, Massachusetts told NBC10 Boston, “The recent norovirus cases are probably another example of seeing re-emergence of common infections as we continue to emerge from our COVID-19 shells… There were periodic localized outbreaks of norovirus infection all the time pre-COVID, so not surprising that we’re seeing them again.”

According to the Mayo Clinic, norovirus symptoms usually last for only a few days; those infected should stay hydrated as much as possible, since dehydration can cause complications and possible hospitalization. It is also important to isolate and stay home from work or school, if possible, to avoid infecting others since the virus spreads so quickly.

“Set a timer on your phone if you must to say it’s time to try to eat something, or it’s time to at the very least to drink something to remain hydrated. If you can’t keep water down after 24 hours, it’s important to seek help,” says Dr. Jay-Sheree Allen, a Mayo Clinic family medicine physician. “If you are able to keep some things down, but your symptoms persist after 48 to 72 hours, it’s also a wise idea to seek help from a medical professional.”

Norovirus is a difficult virus to kill, so washing hands with soap and water is an important prevention method, since as hand and sanitizer is not as effective against norovirus. Some other prevention tips include washing your fruits and vegetables before eating them, not sharing utensils with those who are sick, avoiding contact with people who are infected, and throughly washing clothes, especially if they’re soiled.