SAN FRANCISCO — A person in San Francisco has been identified as having the first recorded case of the omicron variant in the United States, health officials said Wednesday.

Both California and federal officials suspect the coronavirus variant is likely in other parts of the country by now. They say its presence is a cause for concern but not panic.

THE PATIENT

The infected individual returned home from South Africa on Nov. 22, officials with the Centers for Disease Control and Prevention said.

A few days after arriving in San Francisco, the person began to feel ill and got tested. On Monday, the result came back positive, and the virus specimen was subsequently analyzed and revealed to be the latest named coronavirus strain.

Citing privacy, health officials released few details about the individual. Gov. Gavin Newsom said the person was between 18 and 49 years old.

CONDITION

The person was fully vaccinated and had mild symptoms that did not require hospitalization. Officials said the individual’s condition was improving as of Wednesday.

“The person recently traveled to South Africa and developed symptoms upon their return,” said Dr. Grant Colfax, San Francisco’s director of health. “And they did the right thing and got tested and reported their travel history.”

ANALYSIS

The variant’s arrival was not unexpected. First detected last month, the strain has already been found in roughly two dozen countries around the globe.

“It’s not unexpected that we actually do have a case here in California, and we do expect that, over time, we will have additional cases,” said Dr. Mark Ghaly, the state’s health and human services secretary. “And that’s why we need to keep our guard up.”

WHAT’S NEXT

Much remains unknown about omicron. Answers to the most pressing questions — whether the variant spreads more easily, can cause severe illness or dodge some of the protection afforded by vaccines — likely won’t be known for a few weeks.

There are no signs yet of any larger outbreak in the Bay Area, but local officials said they will be on watch for any new cases.

Both state and local officials say they remain confident that the new variant will not require the reimposition of lockdowns or other restrictions. But they urge the public to get vaccinated.