• Norovirus has surged in the Northeast region of the U.S. in the past few weeks, CDC data shows.
• Norovirus, more commonly known as the stomach bug or winter vomiting illness, is an extremely contagious virus that causes vomiting and diarrhea.
• Experts say “meticulously” washing your hands and avoiding people who are ill are the best ways to stay healthy.

Norovirus, the extremely contagious illness that causes vomiting and diarrhea, has surged in the Northeast region of the United States in the past few weeks, according to recent data from the Centers for Disease Control and Prevention (CDC).

While surveillance data show an increase in positive test results nationwide—as is typical for norovirus during the winter months—northeastern states have been hit especially hard, with a three-week average of 13.7% for positive norovirus tests. Those tests have held above a 10% positive rate since December 2023.

Other U.S. regions have also seen an uptick in norovirus illnesses, just at lower rates. For the past three weeks, southern states have seen positive test rate of about 9.4%, the Midwest is at 10%, and western states have seen a 12.6% positive rate.

Here’s what you need to know about norovirus, the increase in cases in the Northeast, and how best to protect yourself from catching the vomiting illness.

The ‘Winter Vomiting Bug’

Though alarming, the current surge in norovirus cases is typical for this time of year, according to Thomas Russo, MD, professor and chief of infectious disease at the University at Buffalo. You can get norovirus any time of year, but it’s most common in the cooler months. “It’s usually a November to April illness, but it often tends to peak in January,” Russo told Health.

Norovirus is extremely contagious. It only takes a small amount of particles—fewer than 100—to make a person sick; put into perspective, a person with norovirus can shed billions of virus particles in their stool and vomit.

The contagiousness of the virus paired with people being in close quarters during the winter months is often what drives surges in cases. “Social interaction of any sort is going to bring you into contact with people that have this,” infectious disease expert Amesh A. Adalja, MD, senior scholar at the Johns Hopkins Center for Health Security, told Health.

Most commonly, norovirus is spread through direct contact with an infected person, like caring for an ill friend or family member. The virus is also transmitted by eating contaminated foods or drinking contaminated liquids (this commonly happens in restaurant settings), touching surfaces that have norovirus particles on them and then touching your face or mouth, or sharing cups or utensils with a sick person.

Stay Healthy By Protecting Yourself and Others

Though Russo said norovirus is “pretty much everywhere right now,” it (hopefully) won’t be that way for much longer.

Though it’s impossible to predict what will happen, William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, suggested that rising temperatures across the U.S. as we get closer to springtime may help slow down virus spread. “Could it be that this will be limited to the Northeast as the temperature warms up in much of the rest of the country? We hope so,” he said.

In the meantime, the best way to protect yourself against norovirus is to practice proper hygiene—and maybe take it up a notch. "Meticulously wash your hands," suggested Adalja (hand sanitizer does not work well against norovirus). Adalja also said that you may want to avoid eating at restaurants if cases are particularly high in your area, since norovirus is commonly passed by food service workers.

If someone in your house has norovirus, it’s important to thoroughly clean contaminated surfaces with a bleach solution, said Schaffner. Keep other frequently touched surfaces, like doorknobs and remote controls clean, too.

While it’s not an official recommendation, Russo added that wearing a mask and gloves while taking care of someone who is sick may help since the virus can be spread through droplets and particles during a vomiting episode.

There’s no specific treatment for norovirus, but if you do happen to get sick, it’s important to stay hydrated through taking small sips of water or sports drinks, said Russo. If you lose too many fluids through vomiting and diarrhea, you could become dehydrated and possibly need intravenous (IV) fluids to rehydrate.

Washing hands is important advice for sick people too—you can continue to spread the virus for up to two weeks after you start feeling better. People who have been sick with norovirus should also avoid closely interacting with others (preparing food, providing healthcare) for at least 48 hours after symptoms stop.

While most people recover from norovirus relatively quickly, aside from a few “days of misery,” said Schaffner, it can still cause serious illness or death in very young children or the elderly. There are also people with an extreme fear of vomiting, known as emetophobia, which can cause them a significant amount of distress if they vomit or are around someone who vomits.