By Michelle Durham

PHILADELPHIA (CBS) – It’s making the rounds and it’s making people miserable. It’s Norovirus and its victims span the ages from college campuses to long-term care facilities for the elderly as it spreads rapidly, especially among people living in close quarters.

Director of the Division of Infectious Diseases at Thomas Jefferson University Hospital Dr. Kathleen Squires explains why this bug, which causes vomiting and diarrhea, spreads so fast.

“They are excreting it in their stool and if they are vomiting, it’s in the vomit as well. And if they are not rigorous about washing their hands after going to the bathroom or after vomiting, then that virus can be passed from person to person,” Squires explained.

How do you prevent it? Squires says it all comes down to one thing: washing your hands. If you have Norovirus or caring for someone who does, when do you know when you are dehydrated and need to go to the hospital?

“When you can’t urinate any more, when you are thirsty. When you are lying down, you get up and the room spins around you — those are all signs of not enough in our vascular system.”