"We haven't confirmed that its norovirus- but it certainly appears to be norovirus," explained registered nurse Susan Thompson who runs Durham County's communicable disease program.
There's already been five possible cases of norovirus in Durham. The county's still waiting for lab results. But between now and April, Thompson expects that number to go up fast.
"[When the] holiday season begins - people gathering together, sharing food - it's also the time of year where it gets cold and people are inside, so it's perfect environment for norovirus to spread quickly," said Thompson.
The health department is stressing hand washing as the most effective way to prevent norovirus. They say hand sanitizer is not enough.
"The important thing is good old fashion hand washing for 20 seconds - they say to sing happy birthday as you wash your hands," said Thompson.
Day cares, nursing homes, and schools are especially vulnerable to the virus which spreads through contaminated food and drinks - often triggering vomiting and stomach cramps.