Health professionals are noting a surge in a norovirus called “winter vomiting disease,” which spreads through contaminated food and water.
The Centers for Disease Control and Prevention (CDC) monitors wastewater surveillance testing, which has indicated that the virus is spreading earlier and faster than usual.
Reported cases, particularly in Louisiana, Michigan and Indiana, have been surging since October. California, Alabama, Texas and Florida have also been flagged for pockets of outbreaks.
Each year, there are about 2,500 reported norovirus outbreaks in the U.S., according to the CDC.
A variant of norovirus known as GII.17 has begun to raise concerns for health professionals after cases spiked. In 2024, the GII.17 mutation was responsible for about 75 percent of outbreaks, per the health agency.
Prior to that, the GII.4 strain dominated norovirus outbreaks for more than three decades.
“When new strains emerge, people are exposed to a strain that they have not previously been exposed to, and hence are more likely to get infected,” Lee-Ann Jaykus, a professor in the department of food, bioprocessing and nutrition sciences at North Carolina State University, told Newsweek.
