CDC reports surge in norovirus outbreaks in some parts of US

The Centers for Disease Control and Prevention says the number of norovirus cases are increasing in some parts of the country.

The most recent numbers from the federal agency show 91 reported outbreak during the week of Dec. 5, up from 69 outbreaks the last week of November.

Over the past few years, the maximum number of outbreaks during the first week of December is 65.

A norovirus infection is characterized by sudden vomiting and diarrhea. Outbreaks are often seen on cruise ships, in congregate living situations like nursing homes and jails, as well as schools and places where people are close together, according to the Associated Press.