ISTANBUL

Norovirus cases appear to be increasing in various parts of the US, ABC News reported, citing data from the Centers for Disease Control and Prevention (CDC).

More than 90 norovirus outbreaks were reported during the week of December 5, the most recent week for which data is available. Previous years' data for the same December week shows a maximum of 65 outbreaks, according to the CDC.

The number of norovirus outbreaks reported by state health departments within a week of illness onset increased significantly in December, from 69 cases in late November to 91 in early December, CDC data shows.

Earlier this month, at least 80 people became ill with norovirus, which was linked to raw oysters, the media outlet reported on Friday.

Norovirus is the leading cause of vomiting and diarrhea, a highly contagious virus that is the most common cause of viral gastroenteritis, which is an inflammation of the inside lining of the gastrointestinal tract, making it the leading cause of foodborne illness in the US.​​​​​​​