Rates of norovirus in that CDC system have reached levels at or above last season's peak in all regions of the country. Norovirus test positivity rates look to be the worst in the Midwest, in a grouping of states spanning Kansas through Michigan.

The latest wave of norovirus infections have more than doubled last season's peak, the CDC said. Almost 30% of norovirus tests taken the week of new year's were positive for the virus. Rates have reached or surpassed last season's peaks in all regions across the country.

Norovirus cases have surged over double last year's peak, with a new strain, GII.17[P17], driving outbreaks. The Midwest is hardest hit as experts stress precautions.

Norovirus, a familiar and repeat offender, is responsible for many recently increased reports of illnesses in Wyoming, according to the Wyoming Department of Health (WDH).

Infectious disease doctors explain if hand sanitizer kills norovirus, and effective ways to neutralize the stomach bug’s germs, including on surfaces.