Norovirus outbreaks have increased to pre-pandemic levels, CDC data show

Health.com spoke with John Sellick about outbreaks of norovirus, a contagious virus that causes vomiting and diarrhea. Because most norovirus requires person-to-person contact in order to spread, COVID precautions may have contributed to recently keeping transmission to a minimum. "This is a tough little virus. It's what we call an unencapsulated virus and that just goes with the way it reproduces," Sellick said. "It's evolved to be very hardy in the environment, [it's] very difficult to clean up."