Stomach Bug Season: What's Going On?

The U. S. is seeing a jump in norovirus cases, often called the stomach bug. This is according to recent data from the Centers for Disease Control and Prevention (CDC). The bug causes vomiting and diarrhea. It's a big deal because it spreads easily and makes people very sick. The CDC reports that almost 14% of tests for norovirus came back positive in mid-November. This is a big increase from earlier in the year. In August, only about 6. 5% of tests were positive. That means the bug is spreading more now. Norovirus is a big problem in the U. S. It's the top cause of food poisoning. Every year, millions get sick from it. About 2, 500 outbreaks happen each year. This leads to over 100, 000 hospital visits and around 900 deaths. Older adults, young kids, and people with weak immune systems are at higher risk. The bug is most common from November to April. Last winter was especially bad, with a 25% positivity rate in January 2025. Recently, a middle school in Michigan closed for a day to clean after many students got sick. In October, nearly 100 people on a cruise ship also got sick from norovirus. The CDC uses test positivity rates to track diseases. But these rates can change based on how many tests are done. The data comes from labs, hospitals, and health departments. While not perfect, it gives a good idea of what's going on. Norovirus symptoms include nausea, stomach pain, vomiting, and diarrhea. Most people feel sick for one to three days. The bug is very contagious, so it spreads quickly. This is why outbreaks happen often.