Rising Norovirus Cases Prompt Health Concerns in the U.S.

In recent weeks, the United States has witnessed a significant uptick in norovirus cases, as reported by the Centers for Disease Control and Prevention (CDC). Data from the week ending November 15 indicates that nearly 14% of tests for the illness returned positive, a stark increase from earlier this year when the positivity rate was at a mere 6.53%.

During the week in question, over 2,700 tests were conducted, resulting in approximately 380 confirmed cases of norovirus. This surge in positivity highlights the seasonal nature of the virus, which tends to peak from November to April. The CDC has noted that norovirus is the leading cause of vomiting and diarrhea in the U.S. and is responsible for more than 100,000 hospitalizations and around 900 deaths annually.

Norovirus, often referred to as the stomach bug or stomach flu, is highly contagious. Symptoms typically include nausea, abdominal pain, vomiting, and diarrhea, lasting one to three days for most individuals. Vulnerable populations, particularly adults aged 65 and older, young children, and those with weakened immune systems, face a higher risk of severe illness or death from the virus.

The recent rise in cases is concerning, especially given the memory of last winter’s major surge, which saw test positivity rates exceeding 25% in January 2025. Just this month, a Michigan middle school was forced to close for a day due to a rash of illnesses among students, and nearly 100 cruise ship passengers fell ill in October, underscoring the virus’s capacity for rapid spread in communal settings.

Preventative measures are crucial in curbing the spread of norovirus. The CDC recommends frequent hand washing, safe food handling, and regular cleaning of surfaces as effective strategies to reduce transmission. It is also important to note that individuals remain contagious even after symptoms have subsided, necessitating continued vigilance for at least two days post-recovery.

As norovirus cases continue to rise, public awareness and adherence to health guidelines will be vital in managing outbreaks and protecting vulnerable populations. With millions affected each year, the importance of understanding and mitigating the risks associated with this highly contagious virus cannot be overstated.