Recently released data from the U.S. Centers for Disease Control and Prevention (CDC) shows that the U.S. is experiencing an uptick in norovirus cases, especially in the Northeast region.

CDC gathers its data from participating U.S. laboratories that report the number of norovirus tests administered each week, as well as the number of those tests that were positive. Updated February 22, 2024, the latest data shows an average 13.7 percent positive rate for norovirus tests in the Northeast over the past three weeks, followed by the West with a 12.6 percent positive rate.

The spike in positive norovirus test rates has yet to meet March–April 2023 levels, however, which saw positive test rates up to 16.1 percent in the Northeast.

In the U.S., outbreaks of norovirus occur most frequently during late fall, winter, and early spring. According to the U.S. Food and Drug Administration (FDA), adherence to FDA Food Code recommendations for hand hygiene and the exclusion of ill food employees from the workplace have the largest impact on reducing the number of norovirus illnesses among customers.