An older woman in Santa Clara County, south of San Francisco, tested positive for the virus Thursday. She has no history of travel to countries with coronavirus nor a known connection with anyone with the disease, county health officials said at a news conference Friday. Such infections are known as “community spread,” which means that people become infected without knowing how or where they caught a virus.
The woman was initially hospitalized for a respiratory illness and was tested at the recommendation of her physician, an infectious disease specialist.
“This new case indicates that there is evidence of community transmission, but the extent is still not clear,” said Dr. Sara Cody, the Santa Clara County public health director. “I understand this may be concerning to hear, but this is what we have been preparing for. Now we need to start taking additional actions to slow down the spread of the disease.”
The case “does signal to us that it’s now time to shift how we respond to the novel coronavirus,” Cody explained. Actions must include more “surveillance” of public health, diligent prevention by citizens to avoid the disease — such as hand washing — and family preparations to stay at home for periods of time in the event of a disease emergency.
Authorities from the U.S. Centers for Disease Control and Prevention on Wednesday revealed the nation’s first apparent case of community transmission of coronavirus, in a woman in Solano County, about 90 miles north of the new case.
The two cases of the virus, known as COVID-19, mark a troubling evolution of the spread of the disease that’s far more difficult to track and contain. The Solano County woman is reported to be in serious condition.
Two other cases have been reported in Santa Clara County, but the sources of those are known.
“Ultimately, we expect we will see community spread in this country,” Dr. Nancy Messonnier, a director of the CDC’s National Center for Immunization and Respiratory Diseases, said Tuesday. “It’s not so much a question of if this will happen anymore, but rather more a question of exactly when this will happen and how many people in this country will have severe illness.”
The latest case makes 63 confirmed in the U.S. They include 44 Americans repatriated from the Diamond Princess cruise ship off Japan, three repatriated from Wuhan, China, 12 people who returned from travel to China, and two who caught it from a close family member.
The World Health Organization on Friday raised its risk assessment of the coronavirus to “very high” — the highest level short of declaring a pandemic. Officials warned nations that the new assessment should serve as a wake-up call for countries to increase preparedness.
The U.S. stock market was down sharply for the fourth day in the largest plunge since the 2008 financial crisis over fears of the virus and its expected effect on the global economy.