First known California case of UK coronavirus variant detected in San Diego County

The first known case of a new and apparently more contagious variant of the coronavirus in California was found in a San Diego County patient, a county supervisor confirmed Wednesday.

San Diego County Supervisor Nathan Fletcher said at the county's coronavirus briefing Wednesday afternoon that the variant had been detected in a 30-year-old man who developed COVID-19 symptoms on Dec. 27 and tested positive for the coronavirus on Tuesday. Fletcher said a Scripps Research lab was able to confirm by 3 a.m. Wednesday that the strain of virus detected in the man was in fact the variant that was first detected in the United Kingdom, which is believed to be as much as 50% more contagious.

"Because there is no travel history, we believe this is not an isolated case in San Diego County and there are probably other cases of this same strain in San Diego County," Fletcher said.

The variant strain, known as B.1.1.7, first emerged in the UK in September and is now prevalent in southeast England. While it is believed to be more contagious, there is no evidence that it is any deadlier than other strains of coronavirus that are already in circulation in California, Fletcher said.

Patients with the B.1.1.7. strain do not have any symptoms distinct from other coronavirus strains.

"These patients will present the same way or in fact potentially be asymptomatic," Dr. Eric McDonald with the San Diego County Department of Health and Human Services said at the county's coronavirus briefing.

While scientists are hopeful current vaccines will be effective against the UK variant, it's currently unknown what its effects will be.

"I think it's important that we don't try to speculate here," immunologist Dr. Kristian Anderson said at the county briefing. "We are hopeful that this particular lineage will not have any effect or minimal effect on preexisting immunity whether that be from previous infection or whether that be from the vaccination, but it's really important here that we need to wait for the data and the data is going to be here soon hopefully from the UK colleagues first, so we are hopeful within the next week or two we will know more about this. But until then, we are hopeful that it won't effect it but we just don't know."

California Gov. Gavin Newsom had previously announced earlier on Wednesday that the new strain had been found in Southern California.

Newsom made the announcement during an online conversation with Dr. Anthony Fauci, the nation's leading infectious-disease expert.

"I don't think Californians should think that this is odd; it's to be expected," Fauci said.

Another case of the coronavirus variant was also detected in Colorado, it was announced Wednesday.

The Colorado and California cases have triggered a host of questions about how the variant circulating in England arrived in the U.S. and whether it is too late to stop it now, with top experts saying it is probably already spreading elsewhere in the United States.

The confirmed case in Colorado is a National Guardsman in his 20s who hadn't been traveling, officials said. He has mild symptoms and is isolating at his home near Denver, while another Guard member has a suspected case. They had been sent last week to a nursing home struggling with an outbreak.

The case in California comes as the state is consumed by a growing pandemic crisis, including record deaths.

Hospitals are increasingly stretched by soaring infections that are expected to grow in coming weeks. Southern California and the agricultural San Joaquin Valley have what is considered no intensive care capacity to treat patients suffering from the coronavirus. And state health officials remain worried about gatherings tied to New Year's Eve.

But hope is on the horizon as vaccines roll out.

The statewide transmission rate has fallen to the point where one infected person is in turn infecting just one other individual, a development that Newsom called encouraging while warning that rates in central and Southern California remain much higher and the trend could reverse from holiday gatherings.

Associated Press reporters John Antczak in Los Angeles and Olga Rodriguez in San Francisco contributed to this story.