A collected sample is dropped into a medical bag as members of the Wisconsin National Guard medical team assist with free COVID-19 drive-thru testing at Blackhawk Technical College.

Rock County public health officials say they are concerned about the potential for widespread variant coronavirus strains, especially after spring breaks and other travel opportunities.

Officials are monitoring data collected by contact tracers to see if there are connections locally between increased travel and increases in coronavirus cases—especially travel to locations with known variant coronavirus activity, epidemiologist Nick Zupan said.

Of specific concern is Wisconsin’s proximity to Michigan, which has the highest reported COVID-19 activity in the nation as of this week.

The B.1.1.7 variant, which originated in Britain and has been confirmed in Rock County, has been a driver of Michigan’s surge, Zupan said.

He said the health department is exploring ways to spread travel advisory information to Rock County residents.

During a media call Thursday, state epidemiologist Ryan Westergaard predicted that the B.1.1.7 variant will be the predominant strain of coronavirus spreading in Wisconsin in coming weeks.

Variants are concerning because they spread quicker and easier than the coronavirus that originated last spring, officials said.

“This is our new pandemic,” Westergaard said of the variants.

Collecting information from people with positive coronavirus cases is easier than it was during the fall and winter months, when activity surged, Zupan said.

But COVID-19 continues to spread in Rock County. As of Thursday, the county had 263 active and confirmed cases of the disease, about 100 more than a month ago.

Case activity is increasing slightly within the 18- to 25-year-old demographic, Zupan said. He anticipates health officials will communicate with the public if they notice trends related to demographics or behavior.

Some states have seen increased spread of the B.1.1.7 variant among children. An outbreak at a Dane County child care center has infected at least 35 people and exposed dozens more, according to a news release issued Monday by Public Health Madison & Dane County.

Zupan said case activity has risen slightly among children ages 4 to 18 in Rock County but not in a way that is particularly concerning.

In a news release Thursday, Community Action said it is shutting down its Community Kids Learning Center in Janesville until April 20 because of two confirmed cases of COVID-19.

Much of the spread of coronavirus among children occurs at activities or events outside of school, Zupan said.