OKLAHOMA CITY - A new strain of Norovirus is making the rounds.
It's the Sydney strain of the virus and is a nasty stomach bug.
US health officials said it's now accounting for about 60 percent of Norovirus outbreaks.
Dr. Robert Welliver of OU Children's Hospital said it comes on fast.
"Very acute onset of vomiting, so you're fine in the morning and in the afternoon you're acutely sick and you develop some diarrhea," he said. "After that it would generally last for a day or two."
Welliver said it's tough to test for Norovirus but he said chances are good it's in Oklahoma.
"It's hard to say whether we have it or not here but I certainly know people who have illnesses that are very similar to what you get with that," he said.
Doctors said the key to avoiding it is hand-washing and disinfecting.
If you do become ill, you need to keep hydrated.