Cases of norovirus are surging in the United States. It’s the country’s leading cause of foodborne illnesses but there have been even more outbreaks than usual recently — hitting schools, holiday gatherings and cruise ships.

STATEN ISLAND, N.Y. — Norovirus, also known as the stomach flu, rang in 2025 in a big way across the United States, and continues to surge. The highly contagious virus causes vomiting and diarrhea, and a record number of outbreaks have been reported for this time of year, according to recent data.

Surge in Norovirus

Stomach flu cases are on the rise in the Washington metropolitan area and across the United States as cold weather and the holiday season push more people indoors. Nationwide, the Centers for Disease Control and Prevention reported 91 outbreaks of norovirus,