What is Norovirus 2025?

Norovirus 2025 refers to the current global and U.S. season of norovirus infections, a highly contagious viral cause of acute gastroenteritis marked by sudden vomiting, diarrhea, and stomach cramps. It is sometimes called the “stomach flu,” although it is unrelated to influenza and primarily targets the gut rather than the respiratory system.

The virus spreads through person-to-person contact, contaminated food or water, and surfaces, and it is notorious for causing rapid outbreaks in crowded settings such as schools, cruise ships, and long-term care facilities. Because most people with mild illness never get tested, official surveillance captures only a small share of infections, so health agencies rely on outbreak reporting and laboratory networks to track trends.

In the United States, recent data show a clear rise in norovirus activity as the 2025–2026 winter season progresses. CDC data reported by national media indicate that nearly 14% of tests were positive for norovirus in mid-November 2025, roughly double the positivity rate seen about three months earlier, and emergency department visits for gastrointestinal illness have been increasing in several states.

Outbreak reporting through the NoroSTAT network recorded 153 norovirus outbreaks from August 1 to November 13, 2025, a level that falls within the middle 50% of outbreak counts observed over the past decade, suggesting a typical but still significant seasonal burden. At the same time, some regions such as Minnesota experienced intense local surges earlier in the year, with more than 130 outbreaks documented in January 2025 alone, illustrating how quickly norovirus can strain public health resources even in an otherwise average season.

Global Picture and How to Protect Yourself

International surveillance highlights that norovirus 2025 is a concern worldwide, but activity is not uniform across countries. In England, national reports for the 2025–2026 season show that overall norovirus activity remains within expected ranges, with cumulative positive laboratory reports essentially matching the five-season average and recent weeks showing substantially fewer lab-confirmed cases and hospital outbreaks than typical, even as genogroup II viruses continue to dominate.

For individuals and families, the most effective responses are preventive. Frequent handwashing with soap and water, careful cleaning and disinfection of contaminated surfaces, staying home while sick, and avoiding food preparation for others until at least 48 hours after symptoms end all reduce the risk of transmission. Because only a small proportion of infections are ever confirmed by testing, these everyday behaviors are crucial to limiting the impact of norovirus 2025 on households, schools, and healthcare systems.