Norovirus, the highly contagious disease that causes vomiting and diarrhea, has increased in the northeastern United States in recent weeks, according to recent data from the Centers for Disease Control and Prevention (CDC).
While surveillance data shows an increase in positive test results nationwide — as is typical for norovirus during the winter months — northeastern states have been hit particularly hard, with a three-week average of 13.7 percent for positive norovirus tests. These tests have remained above a 10% positive rate since December 2023.
Other areas of the US have also seen an increase in norovirus illnesses, just at lower rates. Over the past three weeks, southern states have a positive test rate of about 9.4%, the Midwest is at 10%, and western states have seen a positive rate of 12.6%.
Here's what you need to know about norovirus, the rise in cases in the Northeast and how to best protect yourself from the vomiting sickness.
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Although alarming, the current increase in norovirus cases is typical for this time of year, according to Thomas Russo, MD, professor and chief of infectious diseases at the University at Buffalo. You can get norovirus any time of year, but it's more common in the cooler months. “It's usually a November to April disease, but it often tends to peak in January,” Rousseau said. Health.
Norovirus is highly contagious. It only takes a small amount of particles—less than 100—to make a person sick. In perspective, a person with norovirus can shed billions of virus particles in their feces and vomit.
The contagiousness of the virus combined with people being in close proximity during the winter months is often what causes an increase in cases. “Any social interaction will bring you into contact with people who have it,” an infectious disease expert Amesh A. Adalja, MD, said a senior scholar at the Johns Hopkins Center for Health Security Health.
Most commonly, norovirus is spread through direct contact with an infected person, such as caring for a sick friend or family member. The virus is also spread by eating contaminated food or drinking contaminated liquids (this usually happens in restaurants), touching surfaces that have norovirus particles and then touching your face or mouth, or sharing cups or utensils with a sick person.
Although Russo said norovirus is “pretty much everywhere right now,” it (hopefully) won't be like that for much longer.
Although it is impossible to predict what will happen, William Schaffner, MD, an infectious disease expert and professor at Vanderbilt University School of Medicine, suggested that rising temperatures in the US as we approach spring may help slow the spread of the virus. “Will this be confined to the North East as temperatures rise across much of the rest of the country? We hope so,” he said.
In the meantime, the best way to protect yourself from norovirus is to practice good hygiene — and maybe get plenty of it. “Wash your hands thoroughly,” suggested Adalja (hand sanitizer doesn't work well against norovirus). Adalja also said you may want to avoid eating at restaurants if cases are particularly high in your area, since norovirus is commonly spread by food service workers.
If someone in your home has norovirus, it's important to thoroughly clean contaminated surfaces with a bleach solution, Schaffner said. Keep other frequently touched surfaces clean, too, such as doorknobs and remote controls.
While not an official recommendation, Russo added that wearing a mask and gloves while caring for someone who is sick can help, as the virus can be transmitted through droplets and particles during a vomiting episode.
There's no specific treatment for norovirus, but if you do get sick, it's important to stay hydrated by drinking small sips of water or sports drinks, Russo said. If you lose too much fluid through vomiting and diarrhea, you may become dehydrated and may need intravenous (IV) fluids to rehydrate.
Hand washing is important advice for sick people, too—you can still spread the virus for up to two weeks after you start feeling better. People who have contracted norovirus should also avoid close interaction with others (food preparation, health care provision) for at least 48 hours after symptoms stop.
While most people recover from norovirus relatively quickly, other than a few “miserable days,” Schaffner said, 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 significant distress if they vomit or are around someone who is vomiting.
