A Santa Clara County woman has been diagnosed with coronavirus without having traveled to areas with outbreaks or coming into known contact with infected individuals, county officials announced Friday. 

She is the second person in the U.S. to be diagnosed without having any known exposure to the disease, after a woman in Solano County, California, was diagnosed on Wednesday. The cases suggest that the virus may already be spreading from person to person within the state. 

“The virus is here, present, at some level, but we still don’t know to what degree,” said Sarah Cody, director of the County of Santa Clara Public Health Department, at a live-streamed press conference Friday afternoon. “An important priority for us is to conduct public health surveillance to determine the extent of what’s happening.”

County officials announced on Saturday afternoon that an adult woman who is a “household contact” of the Santa Clara County woman has also been diagnosed with coronavirus. The second woman “is not hospitalized or ill,” officials said.

On Sunday, they confirmed that three more people have been hospitalized for coronavirus in Santa Clara County. Two are a husband and wife who recently traveled to Egypt; the husband also has chronic health conditions. The third is an adult woman with chronic health conditions; the county provided no further information in her case, writing that “the investigation of this case has just begun.”

The new diagnoses bring the total number of cases in Santa Clara County up to seven, although one infected individual has already recovered. Globally, there are over 87,000 confirmed cases and 2,977 deaths, according to the World Health Organization.

Cody urged individuals “to prepare for the possibility of further spread of the virus,” encouraging schools and businesses to explore options for remote learning and working.

On Friday, the Palo Alto Unified School District received a report that two of its students may have been exposed to coronavirus, according to a message from the superintendent. The message did not specify how the students may have been exposed. 

One of the students attends Palo Alto High School, just steps from Stanford’s campus. Although neither are exhibiting symptoms, both students were sent home immediately and will be excluded from school until the district receives more information. The district does not plan to close schools or cancel any events at this time.

The patient whose diagnosis was announced on Friday is an older adult woman with chronic health conditions who had been hospitalized for respiratory illness, Cody said. Her primary care physician contacted the Public Health Department on Wednesday to request that she be tested for coronavirus, and the Santa Clara County Public Health Laboratory received her lab samples and performed testing on Thursday. 

She is being treated at El Camino Hospital in Mountain View, according to the Mercury News. The Washington Post reported that she is 65 years old.

The new case signals that “it is time to shift how we respond to the novel coronavirus,” Cody said on Friday. 

Cody recommended that individuals continue “straightforward” hygiene practices such as keeping their hands clean, staying home when sick and avoiding touching their faces. Individuals should also begin thinking about family preparedness and making plans for the possibility that they would need to stay home, she said. 

Cody also said that schools should “plan for absenteeism and explore options for learning at home.” Businesses should replace in-person meetings with video- or teleconferencing wherever possible, as well as increase remote working options and modify absentee policies.

There are no recommendations yet for students to stay home from school or work, Cody said. 

The Daily has reached out to the University for comment. 

Stanford updated its travel guidelines on Friday to add Italy and Iran to the list of restricted countries along with China and South Korea. All community members who are returning from travel from any of those countries or who have come into contact with someone who has are asked to self-isolate for 14 days. 

In spring break travel guidelines emailed to students on Tuesday, Vaden Health Center director James Jacobs also recommended against travel to Hong Kong, Macau and Japan. 

On Tuesday, Stanford also announced that it would be suspending its Florence, Italy, study abroad program after Italy emerged as the center of the virus’ spread in Europe. The University will make a decision whether to proceed with spring study abroad programs by March 20. 

“Our decision-making is guided by public health experts at and beyond Stanford as well as restrictions or recommendations put forth by intelligence sources,” wrote Adrian Doyle, Bing Overseas Studies Program Associate Director for Student and Academic Services, in an email to Oxford spring quarter students. “Stanford continues to assess risk based on the number of cases, community spread, public health infrastructure, as well as other factors.”

This article has been updated to include information about the Santa Clara County woman whose diagnosis was announced on Saturday.

Contact Erin Woo at erinkwoo ‘at’ stanford.edu.