'We have moved from containment to mitigation': Solano Co. declares coronavirus emergency

In this image from a scanning electron microscope, the new coronavirus is in orange. In this image from a scanning electron microscope, the new coronavirus is in orange. Photo: Elizabeth Fischer / Courtesy NiAID Photo: Elizabeth Fischer / Courtesy NiAID Image 1 of / 22 Caption Close 'We have moved from containment to mitigation': Solano Co. declares coronavirus emergency 1 / 22 Back to Gallery

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Solano County declared a state of emergency Thursday, a day after a resident tested positive for coronavirus with no known connection to travel abroad or another known case.

Dr. Bela Matyas, Solano County's public health officer, said in a press conference Thursday night that the risk to the community remains low and that the declaration allows the county to investigate the situation and motivate resources.

"We are taking this situation seriously and are taking steps necessary to protect the health and safety of Solano County residents," Matyas said. “It is important to recognize that we have moved from containment to mitigation. We are investigating potential exposures, and ensuring that proper evaluation and care are provided if they become sick.”

Matyas confirmed that the female patient is the first coronavirus patient with unknown exposure and said she that is "a person who genuinely acquired the virus in the community."

Officials at the conference said the woman exposed as many as 100 health workers to the virus. "We're evaluating everyone who had contact, and their risk for exposure is being assessed," Matyas said. "Some are in isolation and some are in quarantine. Hospitals are working aggressively to identify those individuals."

The patient's family is in isolation, and state and federal officials are aggressively trying to locate everyone who came in contact with the Northern California woman.

The patient first arrived at the NorthBay VacaValley Hospital in Vacaville on Feb. 15 and spent three days there. Matyas said she wasn't tested for COVID-19 because her condition wasn't severe and there weren't any known risk factors for the virus.

After the patient's condition worsened, she was transported to UC Davis Medical Center in Sacramento County on Feb. 19, but it wasn't until four days later that the CDC heeded a request to test the patient for coronavirus, according to an email sent to employees Wednesday by the hospital’s interim CEO Brad Simmons and David Lubarsky, CEO of UC Davis Health.

The patient arrived on a ventilator, and special protection orders were issued “because of an undiagnosed and suspected viral condition,” according to the email.

The hospital asked the Centers for Disease Control and Prevention to test for the coronavirus, but testing was delayed until Sunday “since the patient did not fit the existing CDC criteria for COVID-19,” the email said.

The CDC confirmed the test was positive on Feb. 26.

Despite the delay in testing, UC Davis Medical Center, which has treated other coronavirus patients, has been taking infection prevention precautions since the patient arrived. The email said officials believe that there was "minimal chance" others at the facility were exposed to the virus.

“Nevertheless, a small number of medical center employees have been asked to stay home and monitor their temperatures,” the email said.

While 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, Maytas said the patient has no connection to the base or anyone who worked there.

Coronavirus has infected more than 81,000 people in three dozen countries, with the vast majority in mainland China.

The new virus is a member of the coronavirus family that can cause colds or more serious illnesses such as SARS and MERS.

The virus can cause fever, coughing, wheezing and pneumonia. Health officials think it spreads mainly from droplets when an infected person coughs or sneezes, similar to how the flu spreads.

Officials are advising people to take steps to avoid infection with coronavirus or other respiratory infections like a cold or the flu, including washing hands with soap and water, and avoiding close contact with people who are sick.

The Associated Press contributed to this story.

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