First Sonoma County resident infected with coronavirus through unknown community transmission

For more stories about the coronavirus, go here .

Questions or concerns can be directed to the county's 24-hour information hotline at 211 or 800-325-9604. You can also text "COVID19" to 211211 for coronavirus information.

• Get a flu shot, and it's not too late this season

• Washing hands frequently with soap and water for at least 20 seconds

Local health officials urge practicing good hygiene to reduce the risk of becoming infected with a respiratory virus, such as the flu or coronavirus. This includes:

Sonoma County has confirmed its first case of coronavirus contracted through an unknown local source, an adult who tested positive after the county expanded testing last week, public health officials announced Saturday.

The new case marks an escalation in the local battle against a highly contagious, infectious disease that has put the world on edge. It was detected through the county Department of Health Services’ enhanced surveillance testing, launched Thursday to help determine if the virus was being transmitted in the community without anyone knowing it.

Though disturbing, discovering an unsuspected case “was the whole point of this surveillance,” health department spokesman Rohish Lal said.

“This is basic epidemiology,” he said. “This is what you do in a situation like this.”

Such testing has only recently become possible because of the arrival of test kits from the Centers for Disease Control and Prevention after a long delay.

The individual involved had symptoms that put him or her in line for testing but which were not serious enough to require hospitalization as of Saturday night, when Sonoma County Health officials announced the new case.

A second person associated with the infected person also has been tested. Those results are pending, county health officials said.

That person is without symptoms and self-quarantined, health officials said.

Officials also said they are contacting “all individuals” who may have had contact with the person whose case is confirmed to advise them of possible exposure.

Health officials may reveal more at a news conference scheduled for noon Sunday. The news conference will be broadcast live on the County of Sonoma’s Facebook page.

The newly diagnosed individual is the fourth person in the county known to be infected with the virus since it originated in China in January and spread around the world.

Two earlier Sonoma County cases involved patients who traveled aboard the Grand Princess cruise ship during a 10-day voyage from San Francisco to Mexico in February, when another passenger, a Rocklin man who later died, was ill.

Another patient, a former passenger on the Diamond Princess in Japan, also was hospitalized in Santa Rosa after being airlifted to Travis Air Force Base near Fairfield and then transferred to Sonoma County.

Health officials have declined to disclose the hospitals involved or say anything about the patients, even their genders, citing privacy provisions in the 1996 Health Insurance Portability and Accountability Act.

Marin County Public Health Officer Matt Willis also announced that county’s first incidence of community transmission on Saturday, describing two new cases with no known exposure to others. Marin County now has five cases.

“The first cases of community transmission of COVID-19 in Marin means we’re in a new stage of working to mitigate spread,” Willis said in a written statement.

“We’ve been anticipating this. This is why we took big steps this week, including limiting large gatherings and closing classrooms.”

Neither of the newly diagnosed individuals are hospitalized, but they are quarantined at home until they are no longer infected, Willis said.

Napa and Mendocino counties have no confirmed cases of COVID-19.

State and federal health officials have been ramping up emergency measures as coronavirus has spread throughout the continent, as countries like Italy and Spain have begun shutting down public life entirely.

The virus has become pervasive enough that last week the World Health Organization declared the coronavirus a pandemic.

But testing in the United States hast been limited because of a lag in availability of test kits from the CDC. Sonoma County health officials finally got the capacity to test 200 people last weekend and began testing Saturday.

On Thursday, Interim Public Health Officer Sundari Mase launched the surveillance program, through which 20 people displaying flu-like symptoms were singled out for testing at each of three or four hospitals, community care clinics or urgent care facilities, Lal said. Ten from each group were to be otherwise healthy individuals, and 10 were to be from high-risk groups, meaning above 60 years old or with underlying medical problems, such as heart disease, that made them especially vulnerable to coronavirus, he said.

One of the test subjects is the individual who tested positive for coronavirus Saturday. County officials did not disclose which of the two groups, or from which location, the positive test came from.

Lal said other tests are still pending, and the program will continue until it is no longer warranted.

Healdsburg resident Batja Cates said she is in her late 70s and has underlying health conditions, so she already is taking care in her movements out in the world.

But she said she wished the county would provide information about where the new case surfaced so that she and others could strategically avoid areas that might increase their exposure.

“I think it is short-sighted of them not to enable defensive social distancing,” she said. “This feels like Russian Roulette to me.”

But health officials have said all people should reduce social contacts, maintaining 6 feet of space between themselves and others in public and frequently washing hands and surfaces to avoid transfer of germs.

On Friday, Mase, the county’s interim health officer, issued an ordinance that calls for the cancellation of any gatherings of 250 individuals or more within the county. It excludes activities such as school attendance, work, courthouses and correctional sites.

You can reach Staff Writer Mary Callahan at 707-521-5249 or mary.callahan@pressdemocrat.com. On Twitter @MaryCallahanB. Staff Writer Bill Swindell contributed to this report.