State health officials have confirmed that a more contagious variant of the virus that causes COVID-19 has been detected in Wisconsin.

The variant, known as B117, was found Tuesday, the state Department of Health Services said in an announcement.

“We already know that COVID-19 is easily transmitted through respiratory droplets, and with this new variant appearing to be even more infectious, taking preventative measures like wearing a mask and physically distancing are even more important,” DHS Secretary-designee Andrea Palm said.

State epidemiologist Ryan Westergaard said the variant was detected through routine genome sequencing of a positive COVID-19 test for an Eau Claire County resident.

Westergaard said he had no information about the person other than he or she had traveled internationally in the two weeks before he or she was tested.

Elizabeth Giese, director of the Eau Claire City-County Health Department, said the person tested positive for COVID-19 at the end of December when the individual returned from the trip.

Contact tracers determined the individual had interacted only with members of his or her own household and that all of them quarantined in their home, Giese said. She declined to release any further information about the person.

“We do not expect from this specific case for there to be community spread,” she said. “We did identify all the close contacts. They did all stay home. (But) we also know this variant strain is likely going to be circulating across our state.”

The variant was first discovered in England in November and December. It has since turned up in Colorado, California, Florida, Minnesota, New York and Georgia.

Health officials have said the variant is more easily transmissible—Westergaard said researchers believe it’s nearly twice as contagious as the original COVID-19 virus—but it isn’t any deadlier and vaccines should be effective against it.

Westergaard said researchers aren’t sure why the variant is more contagious. It might attach more tightly to cell receptors in the body or it might take fewer variant particles to cause infection than the original COVID-19 virus, he said.

Only about 1% of positive tests in the state are routinely sequenced, which means the variant could be more widespread than anyone realizes, Westergaard said. He cautioned people to continue to wear masks, stay socially distanced and avoid gatherings.

“It could be spreading in a more generalized way,” he said. “Is more of it out there? We don’t have enough data to estimate how prevalent it is, but it’s probably more than we know about.”

The number of COVID-19 infections in the state continued to drop for the fifth straight day. State health officials reported 2,134 newly confirmed cases and 37 more deaths Wednesday. The state has now seen 513,270 infections and 5,248 deaths since the pandemic began in March.

Rock County reported 27 new COVID-19 cases and one additional virus-related death Wednesday, state data shows.

A total of 12,968 cases and 126 deaths have been reported in Rock County since the pandemic began last spring. Some 66,421 negative tests have been reported along with 12,003 recoveries and an estimated 839 active cases in the county.

In numbers reported Wednesday, 18% of tests in the county were positive. The statewide seven-day test positivity average is now 9.4%.

Rock County reported 38 hospitalizations related to COVID-19 as of Wednesday, up from 35 across the county Tuesday.

As of Wednesday, Green County reported 2,495 cases and 10 deaths, and Walworth County reported 8,219 cases and 107 deaths, according to state data.

The Associated Press contributed to this story.