SACRAMENTO (CBS13) — A person has tested positive for the novel coronavirus in Northern California, making this the first possible instance of “community spread” of the virus, according to the CDC.

According to the California Department of Public Health, the patient is a resident of Solano County who is receiving care in Sacramento County. The patient is being treated at UC Davis Medical Center in Sacramento, the hospital confirmed.

The CDC said the person “did not have relevant travel history or exposure to another known patient with COVID-19.”

This is the 15th novel coronavirus case in the United States. According to officials, the patient tested positive through the public health system somewhere in Northern California.

According to an internal memo from UC Davis Medical Center, the patient was transferred from another hospital last Wednesday and was already intubated and on a ventilator. The patient was tested for coronavirus on Sunday and the test came back positive on Wednesday.

READ: Facebook Bans Ads With False Claims About Coronavirus

The memo also states that when the patient arrived in Sacramento, doctors asked public health officials if this case could be coronavirus and requested coronavirus testing, but the test was not given immediately because the patient did not fit the existing CDC criteria for the novel coronavirus.

This appears to be the first case of coronavirus in the U.S. of an unknown origin. Other cases are either travel-related or spread person-to-person.

Dr. Dean Blumberg is the Chief of Pediatric Infectious Diseases at the UC Davis Children’s Hospital. He is worried about widespread transmission because if no one has been exposed to the new virus, “that means we are all susceptible to it, and that means if we do get a significant exposure, we will get infected.”

Northern California is now at the center of a potential outbreak.

“We only have this one confirmed case of community transmission, but it suggests that we don’t know where they got it from, so the person who exposed them, so there’s probably other cases in the community that we don’t know about,” Blumberg said.

He worries we are not prepared.

“We don’t have that much data, so we don’t really know how many symptomatic, or asymptomatic patients there are in the community right now. The testing is very limited. We would like to have more widespread testing so we know where this virus is — who’s sick and who is at risk,” Blumberg said.

READ: Sacramento Health Officials Do Not Plan On Declaring State Of Emergency Over Coronavirus

Currently, there is one other person being treated for the virus in Sacramento County. The confirmed case is travel-related. Officials said the individual returned from China to the United States on Feb. 2 and has since self-quarantined and taken precautionary measures upon their return home. The individual began displaying mild symptoms during the self-quarantine.

READ ALSO: Sacramento DOJ Employee Telecommuting After Brief Exposure To Family Member With Coronavirus

According to the CDC website, of the 14 other confirmed cases the U.S., 12 are travel-related, and two are person-to-person spread. More than 400 people have been tested for the virus.

US Congressman John Garamendi tweeted about the new case of coronavirus Wednesday night. Garamendi said he is in contact with the CDC and California officials about the case.

1/2 I am aware of reports that a Solano County resident has tested positive for COVID-19 strain of Coronavirus. I am in close contact with the U.S. Centers for Disease Control and the State of California and will pass along any updates as they become available. — John Garamendi (@RepGaramendi) February 27, 2020

Gov. Gavin Newsom and state health officials have scheduled a briefing on Thursday morning to talk about the response to the coronavirus. The briefing is set to begin at 10:30 a.m.