CDC Data Show Stomach Bug Circulating in Northeast

Norovirus, an extremely contagious illness that causes vomiting and diarrhea, has seen a recent surge in the Northeast region of the United States, based on recent data from the Centers for Disease Control and Prevention (CDC).

Surveillance data indicates a nationwide increase in positive test results for norovirus, which is typical during the winter months. However, northeastern states have been particularly impacted, with a three-week average of 13.7% for positive norovirus tests. This positive rate has been above 10% since December 2023.

Other regions of the U.S. have also experienced an increase in norovirus cases, although at lower rates. Over the past three weeks, southern states have had a 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 should know about norovirus, the rise in cases in the Northeast, and how to best protect yourself from catching this vomiting illness.

Although concerning, the current increase 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. Norovirus can be contracted throughout the year, but it’s most common in colder months. “It’s usually a November to April illness, but it often tends to peak in January,” Russo told Health.

Norovirus is highly contagious, with just a small number of particles—less than 100—capable of causing illness. A person with norovirus can shed billions of virus particles through their stool and vomit.

The virus’s contagious nature, combined with people being in close proximity during winter, often leads to spikes in cases. “Social interactions of any kind will expose you to people who have this virus,” said infectious disease expert Amesh A. Adalja, MD, senior scholar at the Johns Hopkins Center for Health Security, in an interview with Health.

Norovirus is most commonly spread through direct contact with an infected person, consumption of contaminated foods or liquids, touching surfaces with virus particles and then touching your face or mouth, or sharing items with an infected individual. Contamination often occurs in restaurant settings.

Despite norovirus being prevalent right now, its spread may decrease in the near future, according to Russo.

While the future is uncertain, William Schaffner, MD, an infectious disease specialist and professor at the Vanderbilt University School of Medicine, suggested that as temperatures rise across the country towards spring, the spread of the virus may slow down. “It’s possible that the increase will be limited to the Northeast as temperatures warm up in other parts of the country. We hope for that,” he mentioned.

In the meantime, the best defense against norovirus is practicing good hygiene—perhaps even more diligently. “Thoroughly wash your hands,” recommended Adalja (hand sanitizer is not very effective against norovirus). Adalja also advised avoiding dining out if cases are high in your area, as norovirus is commonly transmitted by food service workers.

If someone in your household has norovirus, it’s crucial to clean contaminated surfaces thoroughly with a bleach solution, as recommended by Schaffner. Additionally, ensure that frequently touched surfaces like doorknobs and remote controls are kept clean.

Though not an official recommendation, Russo suggested that wearing a mask and gloves while caring for a sick person might help, as the virus can spread through droplets and particles during a vomiting episode.

There is no specific treatment for norovirus, but if you do fall ill, maintaining hydration by taking small sips of water or sports drinks is important, according to Russo. Severe dehydration may require intravenous fluids for rehydration.

It’s crucial for sick individuals to continue washing their hands, as the virus can be contagious for up to two weeks after symptoms improve. Those who have had norovirus should also avoid close contact with others (handling food, providing healthcare) for at least 48 hours after symptoms cease.

While most people recover from norovirus relatively quickly, experiencing only a few days of discomfort, severe illness or even death can occur in very young children or the elderly. Additionally, individuals with emetophobia, an extreme fear of vomiting, may experience significant distress if they vomit or are around others who do.