Norovirus Cases Surge as Holiday Season Approaches

As the holiday season begins, cases of the highly contagious stomach virus known as norovirus are on the rise, according to new data from the Centers for Disease Control and Prevention (CDC). The latest statistics reveal that during the week of November 15, 2025, one in seven tests for norovirus returned positive, marking a significant increase in infections. This rise equates to approximately 380 positive results out of over 2,700 tests conducted, representing a 24 percent increase from the previous week.

The CDC’s findings highlight a concerning trend, with norovirus cases up by one-third compared to the same period last year when only one in ten tests were positive. Furthermore, positivity rates have doubled since August, when the virus was at its lowest prevalence for the year. Last December, the infection rate peaked at one in four tests, indicating a troubling resurgence as families gather for holiday festivities.

The symptoms of norovirus, including severe vomiting and diarrhea, typically manifest between 12 to 48 hours after exposure. While most individuals recover within a few days, the virus poses a serious risk, claiming approximately 900 lives annually, predominantly among adults aged 65 and older. The illness is known for causing severe dehydration, which can lead to life-threatening complications.

Dr. Olalekan Otulana, a physician at Cassiobury Court in the UK, emphasized the importance of hygiene in preventing the spread of norovirus. He stated, “The most effective protection comes from handwashing with soap and water, especially before eating and after using the toilet.”

Increased Risk During the Holiday Season

The holiday season creates ideal conditions for the virus to spread, as people gather indoors for celebrations and travel. Norovirus is transmitted through contact with contaminated surfaces, food, and direct interaction with an infected person’s vomit or feces. The CDC estimates that norovirus affects about 21 million Americans each year, leading to around 2 million visits to healthcare providers.

Dehydration is a critical concern associated with norovirus. The rapid loss of fluids and electrolytes due to vomiting and diarrhea can result in dangerously low blood pressure and reduced blood flow to vital organs. It can also lead to serious health issues such as seizures and loss of consciousness. Given these risks, health experts are urging the public to prioritize sanitation.

Recent data from the CDC’s National Respiratory and Enteric Virus Surveillance System (NREVSS) indicates that the positivity rate for norovirus tests increased from 11 percent during the week of November 8 to 14 percent in the following week. The lowest positivity rate recorded this year was 6.5 percent in August.

Understanding Seasonal Variations

The increase in norovirus cases is attributed to a combination of seasonal factors and shifting immunity patterns. Dr. Otulana noted that “norovirus thrives in winter as people move indoors and mix more closely, making transmission easier.” Variations in circulating strains of the virus can also affect immunity levels, leading to sharper spikes in infections.

As families prepare for gatherings during the holidays, experts urge everyone to remain vigilant about hygiene practices. Handwashing, rather than relying solely on hand sanitizers, is crucial for effectively removing virus particles from the skin. With the rising number of cases, taking these precautions can make a significant difference in preventing the spread of norovirus.