Norovirus wave now more than double last year's peak, in CDC's data

This winter's wave of norovirus infections has reached levels that are now more than double last season's peak, in figures published Monday by the Centers for Disease Control and Prevention tracking the notorious stomach bug.

Nearly 28% of norovirus tests run over the week of the New Year's holiday came back positive for the highly contagious virus, which is the leading cause of foodborne illness like vomiting and diarrhea in the U.S.

That is more than double the 13.52% of tests coming back positive reached during the peak of last season's wave in March, according to data from public health laboratories around the country tallied by the CDC.