FOX 2 - It's been nearly three weeks since the first Michigan case of the UK COVID-19 variant was identified.
"It's a stark reminder that this virus is not done with us," said Susan Ringler Cerniglia, Washtenaw County Health Department.
And since that first case - more have been identified
"At this point, we are aware of 21 cases that have been identified as variant in that community," said Cerniglia.
But as the investigation of that cluster continues, healthcare professionals believe the woman who traveled to the UK may not be the only source.
"We may have more than one introduction of the variant in that community," she said.
As variants continue to emerge around the globe, Washtenaw County says the race is on to test more of the county at large so the spread does not continue.
"Every weekend since the variant was identified we have offered pop-up testing no cost," she said.
Learning if the variant is present requires additional testing of a positive case making it a challenge to identify.
"We're not sure how many variants we have because it takes a lot to track down," said Dr. Matthew Sims, director of infectious disease research at Beaumont Health.
As doctors learn more about the variants they say the need to get vaccinated is key.
"It appears to be effective against the UK variant," Sims said. "And the Pfizer and Moderna vaccines may have a somewhat diminished effect against the South African and maybe the Brazilian variant."
But as health departments deal with a shortage in vaccine doses, many say to remain vigilant.
"Strategies that we know prevent the spread, masking, social distancing, avoiding large gatherings, hand washing, and isolation protocols," said Cerniglia.