Norovirus is sickening hikers in Southern California and showing up at high levels across much of the country.

The highly contagious virus can spread quickly in communities, especially where people gather closely together.

It is winter, and a new strain of norovirus called GII.17[P17] is spreading across the U.S. including the northeast. MedStar Health Urgent Care in our region is experiencing an uptick in norovirus ...