Cases of norovirus are surging in some parts of the United States, with 91 outbreaks as of early December 2024, according to the Centers for Disease Control and Prevention (CDC). Norovirus is often transmitted through fresh food or water, and long-term care facilities, childcare centers, and cruise ships tend to be the most common settings of outbreaks. The most common symptoms include diarrhea, vomiting, nausea, and stomach pain. Each year, there are about 2,500 reported norovirus outbreaks in the United States, typically occurring from November to April. “This year the number of reported norovirus outbreaks have exceeded the numbers that we’ve seen recently and in the years before the pandemic,” CDC said in a statement reported by NPR. The news outlet also reports that about 900 people aboard cruise ships were diagnosed with norovirus in December 2024, alongside an unusually high number of outbreaks for the year overall. One incident involved the Queen Mary 2, in which 13% of the ship’s passengers and 5% of the crew were infected.
Testing protocol: Reverse transcription real-time polymerase chain reaction (RT-qPCR) assays are the preferred method to detect norovirus. Clinicians can access norovirus lab testing recommendations from the agency on the CDC website. The gastrointestinal condition leads to 465,000 emergency department visits each year, mostly in young children.