The new, potentially more contagious variant of the coronavirus first identified in the United Kingdom has been found in California, Gov. Gavin Newsom said Wednesday.

He did not specify where in the state the variant was identified, but San Diego County officials announced later in the day that they had confirmed the strain in a 30-year-old man who tested positive there after developing symptoms Sunday.

Officials said the man had “no travel history.” As a result, “we believe this is not an isolated case in San Diego County,” Supervisor Nathan Fletcher said during a press conference.

“While it’s been pointed out that there is not yet evidence that the strain has any more severe symptoms, there is significant evidence that it does spread considerably faster, that it is much more contagious,” he said.

That’s all the more reason why county officials “continue to encourage the public and plead with the public to please come together, especially over the next 72 hours and the New Year’s holiday, to please follow the public health order,” Fletcher added.

The first reported U.S. case of COVID-19 caused by the variant was detected in Colorado, officials there announced Tuesday.