California Governor Gavin Newsom said in a press conference Thursday that at least 8,400 people are being monitored for new coronavirus in the state.

The news comes a day after the Centers for Disease Control announced what's being called the first American case of unknown origin. That Solano County resident is being treated at UC Davis Medical Center near Sacramento.

State and federal health officials are trying to locate everyone who came in contact with the Northern California woman. She had no known connection to individuals who traveled abroad or other known causes.

The woman lives in Solano County, home to Travis Air Force Base, where dozens of people infected in China or on cruise ships have been treated. But Sonia Angell, director of the California Department of Public Health, said there was no evidence the woman had any connection to the base.

"We are not overreacting, but we are not underreacting," Newsom said. "Yesterday's case generated a lot of attention, but we all knew this was inevitable."

Newsom declined comment when asked by reporters to name the community in Solano County where the woman is from. He urged people to take precautions while emphasizing that the risks to public health are low. He said there was no need to declare a public health emergency.

“Everybody in this country is rightfully anxious about this moment,” Newsom said. “I think they should know we are meeting this moment with the kind of urgency that is necessary and I don’t want to over extend the anxiety.”

Newsom said a total of 33 people in California have tested positive for the virus and five of those were moved out of the state.

Newsom said the state has only received about 200 testing kits for the virus, an amount he called “simply inadequate.” But he said federal officials have promised him the state will get many more soon.

Newsom said the state is collaborating with the Trump administration and noted that many flights with American evacuees from China have been taken in and cared for at Travis AFB as well as other bases in the state.

Watch the press conference here.

The Associated Press contributed to this story.

Amy Graff is a digital editor at SFGATE. Email her: agraff@sfgate.com.

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