CLICK HERE if you are having a problem viewing the video on a mobile device

With four of the country’s 11 confirmed cases, Northern California as of Monday had become home to the U.S.’s highest concentration of the coronavirus, a distinction that public health officials say they have been preparing for given the region’s close ties to China.

Santa Clara County Health Officer Sara Cody said she wasn’t surprised as she announced the first confirmed case in the Bay Area Friday in a local man who had returned from traveling in China, where the disease outbreak originated. Her department had “been preparing for this possibility for weeks, knowing that we were likely to eventually confirm a case.”

In the days since, a second Santa Clara County case and two more in neighboring San Benito County have been confirmed, including the second-known case of person-to-person transmission within the U.S.

“We have a lot of residents with families in Asia and a lot of business travel, high-tech travel,” Cody said Monday. “I’d be quite surprised if we don’t have additional cases.”

The situation is rapidly evolving. Airlines are canceling most flights between the Bay Area and China, and the U.S. has undertaken extraordinary measures to slow the spread of the virus in North America, barring entry to most non-citizens who visited China in the past two weeks.

Four military bases — including Travis Air Force Base in Fairfield — were selected to house individuals who were evacuated while traveling overseas due to the virus.

According to a Travis Air Force Base Facebook post, the base was selected to assist the Department of Health and Human Services at the request of Defense Secretary Mark Esper to provide housing for at least 250 people at four different Department of Defense installations through Feb. 29.

According to a Twitter post by Jonathan Rath Hoffman, Esper’s public affairs assistant, the other three bases were the Marine Corps Air Station Miramar in San Diego, Lackland Air Force Base in Texas and the 168th Regiment Regional Training Institute in Colorado.

Most of the 17,000 cases worldwide have been in China, where more than 300 people have died from the virus since the outbreak erupted in the city of Wuhan, about 500 miles west of Shanghai.

But the Philippines over the weekend confirmed the death a 44-year-old man there from Wuhan — the first fatality outside of China — and his 38-year-old female companion, also from Wuhan, has also tested positive for the virus and was hospitalized in Manila.

In the U.S., two cases have been confirmed in Southern California in addition to the four in Northern California. Two have been confirmed in Illinois and one each in the states of Washington, Arizona and Massachusetts.

In the Bay Area’s Chinese American communities, fears are running high. At Pacific Rim Plaza in north San Jose, business has been down all weekend at restaurants and shops, retailers say.

Henry Pei, who owns a vitamin supplement store called Healthsource U.S.A. at the strip mall on Hostetter Road, posted handwritten signs in Mandarin on the door and at the counter of his shop warning people to stay away if they have been to China over the past two weeks.

“Business has almost stopped,” said Pei adding that face masks and hand sanitizer are selling out everywhere. “Everyone is scared.”

At the beauty parlor next door, hair stylist May Yip says she’s especially worried being in such close physical contact with her customers, and she doesn’t like wearing a mask because it’s hard to breathe.

“All my clients are Asian,” Yip said. “I ask if they’re just back from China. “You can’t ask everyone, sometimes they’ll get mad.”

At a travel agency across the street, people are not just canceling trips to and from China, but canceling flights to New York and four-day bus tours to Las Vegas and back.

At Ranch 99 market next door, a list is posted of all the symptoms of Coronavirus and how to help stop its spread. All the employees are now required to wear masks and rubber gloves and follow a long list of rules, including frequently washing their hands.

“Everybody is taking care,” said Ping Lu, the market’s assistant manager.

In a morning news briefing, the U.S. Centers for Disease Control and Prevention said tests are pending on an additional 82 people, and tests have come back negative on 167, though that does not necessarily mean they don’t have the virus because they may not be infected enough for it to register on the test. There are 195 people under quarantine, said Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases.

“This is an unprecedented situation and we’ve taken unprecedented action,” Messonnier said. “This is an aggressive action by the United States, but our goal is to slow this thing down… The growing volume of exported cases to countries throughout the world, and the first death outside of China and person-to-person spread outside of China, including in the U.S., are all cause for concern.”

In San Benito County, officials said a 57-year-old man tested positive after traveling to Wuhan on Jan. 18 and returning on Jan. 24 through San Francisco International Airport, where his 57-year-old wife picked him up. The man developed a cough and low-grade fever the next day. His wife developed symptoms four days later, marking the second known U.S. case of person-to-person infection. Both showed “worsening symptoms,” officials said Monday morning.

San Francisco public health authorities said Monday the couple were transferred to facilities at University of California San Francisco, making their cases more severe than the two in Santa Clara County.

The hospital also treated SARS patients in 2003, it said in a statement, and has instituted “a number of measures” to both screen patients and prevent the virus from spreading.

The two Santa Clara County cases were unrelated. The first involved a man who had returned Jan. 24 from traveling in Wuhan and other parts of China. County health officials would not comment on his age or city of residence, but said he had self-isolated, never required hospitalization and that they are keeping an eye on his condition and the few people with whom they say he had been in close contact.

The second Santa Clara County case confirmed over the weekend involved a woman who is not a local resident but who came to the area on Jan. 23 to visit family after recently traveling to Wuhan. She has stayed home except for two occasions where she sought outpatient medical care, county officials said, and has been regularly monitored and also never was sick enough to be hospitalized.

Cody, the Santa Clara County health officer, said the outbreak is similar to SARS — Sudden Acute Respiratory Syndrome — which also originated in Asia in 2003, and she learned a lot from dealing with it. Early last month, Cody began getting inquiries from local schools and doctors about the novel coronavirus, which is from the same family as SARS.

“I thought, ‘Yep, we’ll have cases,’” she recalled.

The county activated its medical health joint operation center, a process that allows for additional staff to work together on managing the local response, including public communication and outreach to local and federal health officials, businesses and the Chinese-American community, with staff who can speak various languages including Mandarin and Cantonese.

Cody said the preparations have helped, and she stressed that so far the outbreak is not circulating in the community — there have been no cases involving people who haven’t traveled to China or been in close contact with someone who has.

“Sometimes we get unknown new things and we’ve got to be ready,” Cody said. “I feel our department has been prepared. We’ve experienced this before.”

The outbreak has disrupted air travel, particularly in the Bay Area, where business and leisure travelers fill dozens of flights a week.

At San Francisco International, the three weekly flights from Wuhan have been cancelled since Jan. 22, and starting this week, airlines will reduce or altogether eliminate their flights to mainland China, reducing the total from about 88 flights a week to China to 49, spokesman Doug Yakel said.

At Mineta San Jose International, Hainan Airlines temporarily suspended their flights starting Monday through the end of March, said Demetria Machado.

Oakland International does not operate flights to or from China, spokeswoman Keonnis Taylor said, but has been checking with the Department of Homeland Security and CDC for guidance.

The CDC said only U.S. citizens, their immediate family members and legal permanent residents will be allowed into the U.S. from mainland China. Those who traveled to Hubei Province where the outbreak originated within the last two weeks will be quarantined at or near the airport for 14 days. Those returning from other parts of mainland China will be screened for symptoms. If symptomatic they will be detained for further medical evaluation, and if they have no symptoms, will be released but told to stay home 14 days and monitor their health.

Nearly 200 Americans who were evacuated from Wuhan are under a 14-day quarantine at a military base outside Los Angeles — the first by the government in half a century.

Another planeload of passengers from China was expected to arrive Monday at Marine Corps Air Station Miramar near San Diego, but that timing is now “fluid,” according to Rep. Scott Peters. The passengers, who have been screened twice for signs of the virus, will be quarantined at the base for 14 days to ensure they do not pose a health risk to the public, Peters said in a statement Sunday.

As the U.S. steps up its response to the coronavirus outbreak, the Department of Homeland Security is warning airline passengers that their flights may wind up rerouted if officials discover mid-flight that someone on board has been in China in the last 14 days.

And Secretary of State Mike Pompeo said a “handful” of flights will be heading to China to bring Americans back home from Hubei Province, which is at the heart of the outbreak.

The University of California announced it has suspended its spring study abroad programs in China, citing policy in response to “level three” travel advisories from the state department advising against nonessential travel.

Related Articles Coronavirus: Barr slammed for ‘tone-deaf’ comments that compare shelter-in-place ordinances to slavery

Saratoga’s La Mère Michelle reopens after six-month hiatus

Coronavirus rates soar in college towns as students return to campus

Coronavirus: Drugmaker touts potential treatment for less severe cases of COVID-19

Hawaii begins welcoming travelers back: No quarantine, if you have a negative coronavirus test California has the largest Chinese American population in the U.S., and the regions with the largest Chinese American communities are the New York metropolitan area, San Francisco Bay Area and Los Angeles region. Those areas also have frequent business and leisure travel to and from China.

Silicon Valley’s technology industry also has close connections to the country, said Carl Guardino, president of the Silicon Valley Leadership Group, which represents the region’s major technology companies.

Executives at various Bay Area companies have reported various measures, including limiting or suspending travel to and from China and within the country. Some have screened employees returning to work, or asked them to work from home for two weeks if they’ve been to China, canceled trade show appearances and postponed meetings with vendors from China.

“Bay Area business ties to the Pacific Rim and China are quite extensive,” Guardino said, adding that impacts on local companies due to the coronavirus are “equally extensive.”

The Vallejo Times-Herald and the Associated Press contributed to this report.