New Unexplained Coronavirus Cases Raise Specter of Spread

Officials from the three states announced that their testing had found new cases: a high school student from Washington state; an employee of a school in Oregon, near Portland; and a woman in Santa Clara County, California, in the heart of Silicon Valley.

Sixty-five cases of the virus have been reported in the United States, but until this week, all of the cases could be explained by overseas travel or contact with someone who had been ill. The three new cases Friday, and a case earlier in the week, in California, were the first in the United States where the cause was mysterious and unknown — a sign, experts warned, that the virus might be spreading in this country.

“If we were worried yesterday, we are even more worried today,” said Dr. William Schaffner, an infectious disease specialist at Vanderbilt University Medical Center. “Now we have to ask: How widely, really widely, is this virus out there?”

As word emerged of the unexplained cases, local officials scrambled to trace everyone who had come in contact with those who were ill. California health officials said they were increasing testing. And in Washington state, officials suggested that people needed to prepare for the possibility of schools closing and businesses keeping workers home.

“We’re going to be increasingly recommending that people try and avoid crowds and close contact with other people,” Dr. Jeff Duchin, health officer for Public Health Seattle & King County, said. “We may get to a point where we want to recommend canceling large public gatherings — social events, sporting events, entertainment — until we get over a hump of what might be a large outbreak.”

Among those who state health officials said had tested positive for the virus was a student in Washington state who had visited two health clinics and entered his high school building in Snohomish County on Friday before the diagnosis.

In Oregon, health officials said that they had identified a person, an employee of a school, who appeared to have contracted the novel coronavirus more than a week ago and that officials had been unable to determine the source, although the person had no recent travel to China or known contact with someone with the virus.

The Oregon officials said their public health laboratory, which began testing samples Friday, had detected the positive case; the sample will also be tested at the Centers for Disease Control and Prevention for confirmation.

The announcement in Oregon followed one earlier in the day from California, in which officials said another person, in Santa Clara County, with no known links to coronavirus had tested positive for infection with the virus.

On Wednesday, the first such case — with no clear ties to any previous cases or to overseas travel — emerged in Solano County, California, 90 minutes from Santa Clara County.

In the Oregon case, officials said the person had experienced symptoms since Feb. 19 and was employed at a school in Clackamas County, possibly exposing students and staff members. On Friday, officials said, the person was tested for the virus using a kit from the CDC.

Officials in Santa Clara County said Friday afternoon that the newest unexplained case in that state involved a woman with chronic health conditions who was hospitalized for a respiratory illness. The woman also had no history of travel to places like China, nor did she have any known contact with someone who had been overseas or been otherwise infected with the virus, the officials said.

A doctor treating the woman contacted the local public health department to discuss the case Wednesday evening, the officials said, and to request testing for the novel coronavirus, which has killed more than 2,800 people worldwide and sickened some 83,000 people in at least 56 countries.

The Santa Clara public health lab received the specimens Thursday morning and performed the testing, which came back positive later that day. Since then, workers in Santa Clara County have been rushing to identify anyone the woman had been in contact with, and health officials warned schools and businesses to begin preparing for the possibility of absences and to clean surfaces in their institutions.

“This case does signal to us that it’s now time to shift how we respond to the novel coronavirus,” Dr. Sara Cody, the public health director for Santa Clara County, said. “Now we need to add other public health tools to the mix,” including looking systematically for the disease to understand its scope and magnitude, she said.

Santa Clara County, the heart of Silicon Valley, where Google and Apple have their headquarters, also includes San Jose, the 10th-largest city in the nation.

“This has become very real for everyone in our community,” Sam Liccardo, the mayor of San Jose, said Friday evening as he prepared to meet with city staff on the implications of the new case. “There’s certainly a lot of concern, and the concern is justified.”

Emergency medical workers in San Jose who answer calls from people with coronavirus-like symptoms will be instructed to wear protective clothing, he said. “We are going to need to take every reasonable precaution without resorting to panic or finger-pointing.”

There are more known cases of coronavirus in California than in any other state, although most of them have been the result of people traveling abroad. All attention turned to California, Oregon and Washington state as the new cases of mysterious origin emerged.

On Friday, California health officials said they had greatly expanded their ability to test for the virus, and experts said the public health response in the affected counties should include examining specimens of people who may have been hospitalized or killed by a respiratory illness in recent weeks.

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For weeks, local and state health departments across the country have been stretched thin by the coronavirus outbreak, and the cases of unknown origin signaled a new front in their efforts. “Most public health departments can respond to one case or two cases. But it’s going to be many more than that,” said Dr. Joshua Sharfstein, a public health professor at Johns Hopkins.

In Solano County, where the first U.S. case of unexplained origin was announced Wednesday, local officials have fielded calls from scores of concerned residents.

“I’m middling alarmed,” said Rick Lodwick, as he tossed a jumbo pack of sanitizing wipes into the back of his car in the parking of a big-box store in Vacaville.

“When I heard it was here, I thought, ‘We’re going to have trouble,’” Lodwick said.

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Solano County, northeast of San Francisco, is a place of cattle ranches, biotechnology research facilities, a military base and vineyards. An investigation was started into all contacts the sick woman from the county might have had with friends, neighbors and medical workers.

“People are concerned, and they’re paying attention,” said Jeremy Craig, the city manager of Vacaville. “But I don’t think there’s a panic.”

Restaurants were full Friday, the manager of a movie theater said there had been no decline in ticket sales, and it was very rare to see someone wearing a mask.

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Jayleen Richards, public health administrator for Solano County, said her staff of around 200 people was being helped by officials from the California Department of Public Health, the Centers for Disease Control and Prevention, and Travis Air Force Base.

“It’s a lot of work but we’re having the capacity to deal with it right now,” Richards said.

“It’s scary,” said Adrian Obando, a stay-at-home father who was watching his daughter turn cartwheels on the lawn of a park near NorthBay VacaValley Hospital, where the Solano County woman was treated before she tested positive for the coronavirus.

Obando said that he was worried but that he did not think there was much he could do. He said he could see with his children how easily colds and flus spread. “They get sick all the time,” he said.

Dr. Bela Matyas, the public health officer in Solano County, said officials had begun monitoring dozens of people with whom the woman had interacted in recent weeks — including relatives, co-workers and others she might have had contact with through her job — and had asked them to quarantine themselves at home. At least 124 nurses and other health care workers were under self-quarantine, a nurses union reported.

When the authorities announced four weeks ago that hundreds of U.S. citizens traveling from Asia would be quarantined at Travis Air Force Base, in the heart of the county, Solano County was thrust into the national spotlight.

“We saw Solano splashed all over the news with Travis and the quarantine — and we thought well it’s only a matter of time,” said Cricket Kanouff, the president of the Pena Adobe Historical Society, which preserves a home built by early settlers.

“We’d like to be known for our other virtues,” Kanouff said Friday as she placed soap in the bathrooms of the museum at the adobe.

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Several of those quarantined at Travis tested positive for the virus. Yet on Thursday, health officials emphasized there was no indication that the woman had come in contact with anyone at the base, nor had she traveled recently.

Outside the Air Force base there were few signs of concern. Pilots in flight suits greeted one another with handshakes at a nearby fast-food restaurant. No one wore masks during the lunch rush.

The woman in Solano County who has the coronavirus was initially treated in Vacaville and then taken by ambulance to the University of California, Davis Medical Center in Sacramento.

At the hospital Thursday, some workers seemed deeply concerned about possible exposure.

“I’m worried how this will affect my baby,” said Vickie Poncalo, a cashier at the hospital’s cafe who is seven months pregnant.

“Should we be wearing a mask and worrying that people are walking around here?” she asked. “Should I even be here?”

This article originally appeared in The New York Times .