Cases of norovirus are on the rise in the US, on par with seasonal trends, according to the most recent data from the US Centers for Disease Control and Prevention.

In the week ending February 17, more than 12% of tests for norovirus – a common and very contagious virus that causes gastrointestinal symptoms – came back positive, CDC data showed. That’s up from 11.5% the week before. Cases are particularly high in the Northeast, where more than 13% of tests came back positive. Positivity rates in the region have been over 13% since late January.

However, these levels are below what they were at this point last season, when about 15% of tests were positive, both nationally and in the Northeast.

Outbreaks of norovirus are most common in the late fall, winter and early spring, according to the CDC.