California health officials on Friday confirmed a third case of the novel coronavirus in the heart of Silicon Valley, about 80 miles (128 kilometers) south of Vacaville, adding to the more than 30 already confirmed in California.
A Santa Clara county public health department spokesman, Maury Kendall, said the person was isolated at home and that other details would be provided later on Friday. The Washington Post reported the patient did not have a known history of travel to countries hit hard by the outbreak and has no apparent connection to other people infected.
On Thursday, state health officials had pegged the number of people in California with the virus at 33 and announced that a hospitalized woman was believed to be the first in the US to be infected without traveling internationally or being in close contact with anyone who had it.
Residents of the northern California community where the woman lived are at the center of what officials are calling a turning point in the spread of the highly contagious coronavirus.
As infectious disease experts fanned out in Vacaville, some residents in the city of 100,000 stocked up on supplies amid fears things could get worse despite official reassurances, while others took the news in stride.
Vacaville lies between San Francisco and Sacramento in Solano County, in the agricultural Central Valley and near California’s famous wine region. It is about 10 miles (16km) from Travis air force base, which has been used as a virus quarantine location. Public health officials said they can find no connection between the infected woman and passengers on the Diamond Princess cruise ship who were evacuated to the base when the ship was docked in Japan.
The case of the infected woman marked an escalation of the worldwide outbreak in the US because it means the virus could spread beyond the reach of preventive measures like quarantines, though state health officials said that was inevitable and that the risk of widespread transmission remains low.
The Solano county public health officer Dr Bela Matyas said public health officials had identified dozens of people, but less than 100, who had close contact with the woman. They are quarantined in their homes and a few who have shown symptoms are in isolation, Matyas said.
Officials are not too worried, for now, about casual contact, because federal officials think the coronavirus is spread only through “close contact, being within six feet of somebody for what they’re calling a prolonged period of time”, said Dr James Watt, interim state epidemiologist at the California department of public health.
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.
The case in Vacaville also raised questions about how quickly public health officials are moving to diagnose and treat new cases. State and federal health officials disagreed about when doctors first requested the woman be tested.
Doctors at the UC Davis medical center in Sacramento said they asked the US Centers for Disease Control and Prevention to test the woman for the virus on 19 February. But they said the CDC did not approve the testing until Sunday “since the patient did not fit the existing CDC criteria” for the virus, according to a memo posted to the hospital’s website.
The woman first sought treatment at NorthBay VacaValley Hospital in Vacaville, before her condition worsened and she was transferred to the medical center.
A CDC spokesman, Richard Quartarone, said a preliminary review of agency records indicated the agency did not know about the woman until Sunday, the same day she was first tested.
National Nurses United, the union of registered nurses, warned on Friday that Vacaville case highlighted the vulnerability of the nation’s hospitals to this virus and the insufficiency of current CDC guidelines. “Lack of preparedness will create an unsustainable national healthcare staffing crisis,” the union said in a statement.