After a steady increase in the last week in the number of coronavirus cases in California and across the U.S., officials with the Centers for Disease Control and Prevention said Monday the virus is likely to spread.

“We expect to find other cases in the United States,” said Dr. Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases.

The CDC confirmed there are 11 people in the U.S. who have tested positive for the virus, with six cases in California. Five new patients have been discovered in the U.S. since last week’s briefing, officials said, and four of those were in the Bay Area. Health officials in Northern California confirmed three cases Sunday and one Friday, bringing the total number of patients in the state to six.

The CDC said four of the patients in California were recent travelers to Wuhan, China, which has been at the epicenter of the outbreak.


San Benito County health officials said Sunday that a married couple there tested positive for coronavirus. The husband had recently returned from Wuhan and transmitted the pathogen to his wife. The couple were taken to a San Francisco hospital Monday, officials said.

Both patients had previously been diagnosed and were transferred from San Benito County to the San Francisco Department of Public Health’s care, agency spokeswoman Rachael Kagan said.

“They were not diagnosed in San Francisco; they’re not San Francisco residents, but we’re providing the care for them,” she said.

The two patients were moved after they “showed worsening symptoms late Sunday night and were referred for medical evaluation,” according to San Benito County Public Health Services.


“It was then determined that both patients needed to be admitted to a hospital equipped for a higher level of care,” San Benito County Health Officer Dr. Marty Fenstersheib said in a statement Monday. “The patients have been transferred out of San Benito County by specialty ambulance.”

In Santa Clara County, officials on Friday said a male resident who had traveled from Wuhan tested positive. On Sunday, a second case was confirmed in the county after a woman who also had recently traveled to Wuhan became infected.

Two other cases in the state were previously reported in Los Angeles and Orange counties.


Across the U.S., 167 people have tested negative for the virus, while tests are pending for 82 others, the CDC said. Two people were tested in Ventura County for the virus, the Public Health Department said. One tested negative; the other is in isolation until results are finalized. Meanwhile, nearly 200 people remain under quarantine at March Air Force Base in Riverside County after being evacuated from Wuhan amid fears of the outbreak. The mandatory quarantine is the CDC’s first in 50 years.

“We made an aggressive decision in front of an unprecedented threat that action now has the biggest potential to slow this thing down,” Messonnier said.

The new strain of coronavirus, known as 2019-nCoV, has killed more than 360 people since late December. More than 17,400 cases have been confirmed worldwide, with the majority in China.

Individuals who have traveled from an international destination and have visited or passed through mainland China are permitted to fly into 11 airports in the United States: Los Angeles International, San Francisco International, New York-JFK, Chicago O’Hare, Atlanta Hartsfield-Jackson, Daniel K. Inouye International Airport in Honolulu, Seattle-Tacoma International Airport, Dallas/Fort Worth in Dallas, DTW Detroit, Newark Airport in New Jersey and Washington Dulles in Virginia.


Amid hoaxes and misinformation that have spread around coronavirus, the CDC is directing people to its website for updated information.

Times staff writer Luke Money contributed to this report.