A Santa Clara County resident has been diagnosed with the new coronavirus, the first case of the mysterious respiratory illness in the Bay Area, and the seventh case in the United States, public health officials said Friday.
The patient is an adult man who had recently returned from Wuhan, China, the epicenter of the epidemic. Public health officials said he likely was infected there or in Shanghai, where he had also traveled. The man arrived in the Bay Area, at Mineta San Jose International Airport, on Jan. 24 and isolated himself at home from that day on.
Test results confirming he was positive for the virus came back from the U.S. Centers for Disease Control and Prevention on Friday.
“Since we are a large county and many of our residents travel frequently for business and personal reasons, we’re not surprised to be announcing the first case in the Bay Area and Northern California. Actually we’ve been preparing for this possibility for weeks,” said Dr. Sara Cody, the Santa Clara County health officer. “Please know that we do not have evidence to suggest that novel coronavirus is circulating in the Bay Area or Santa Clara County or anywhere in Northern California.
“Although we do understand that this confirmed case may raise concerns, this one case does not change the risk to the general public,” she added. “Our assessment is that the public at large is still at low risk.”
Santa Clara County public health officials are not providing details about where the man who tested positive lives or where he was treated. He has mild illness, Cody said, and has not been hospitalized. He has been seen in an outpatient clinic twice for treatment.
The new coronavirus can cause serious illness and death. Roughly 12,000 cases have been reported worldwide, mostly in China, and 259 people have died. But many infectious disease experts believe the case count is much higher.
Three people have now tested positive for the virus in California: the Santa Clara County man and patients in Orange and Los Angeles counties. Washington state and Arizona each have one patient. Two cases have been reported in Illinois — a woman who had recently returned from China and was infected there, and her husband, who got the illness from his wife.
The Illinois man is the first person confirmed to have been infected by human-to-human transmission in the United States.
Results on an additional 121 possible coronavirus cases are still pending nationwide, according to the CDC. So far, most suspected cases have tested negative for the disease.
Infectious disease experts said Friday that it wasn’t surprising to see a case show up in the Bay Area, where travel to and from China is common. “It would almost be surprising if we didn’t have someone come up positive,” said Dr. Art Reingold, a UC Berkeley professor.
He echoed Santa Clara County public health officials that the threat level to the general public in the Bay Area remains low.
“We know that there will likely be additional importations, of people coming in and developing symptoms and testing positive for the virus,” Reingold said. “We certainly hope that very few of those people will transmit infection here in the Bay Area. Clearly that’s the whole point of isolating sick people. The hope is this continues to be an unusual event.”
Cody said public health officials will now focus on identifying and reaching out to anyone who may have come into contact with the man who tested positive in Santa Clara County. The man has housemates who will be monitored for symptoms. He otherwise had few interactions with other people since he was isolating himself at home, Cody said.
CDC officials will look into flights that the man took on his return to the United States and reach out to passengers he may have come into contact with. Cody declined to identify the airline or flight number of the man’s return trip to San Jose.
The man went directly from the airport to his home on Jan. 24. He stayed home for a few days because of jet lag and because he was not feeling well, Santa Clara County public health officials said. He went for medical care on Jan. 27. Once public health authorities decided he could have coronavirus, they asked him to stay isolated in his home. He was told to remain there until he is no longer considered contagious.
The man arrived in the Bay Area after public health officials had started screening passengers coming from China at certain airports. The San Jose airport was not part of the screening.
At this time, it’s not clear when people who are infected are contagious. It’s likely they are only able to spread the virus while they have symptoms, such as cough, fever and difficult breathing. But cases have been reported of the virus passing from an asymptomatic person to another.
The incubation period for the new coronavirus is thought to be as long as two weeks.
Cody said anyone identified as having close contact with the Santa Clara County man will be asked to isolate themselves for 14 days. “We’re quite lucky in this case in that I think the contact list will be rather short,” she said.
“He has not gone out except to seek medical care, and he has not been very ill,” Cody said. “He’s currently being isolated at home and we will be following him closely at home until he’s no longer infectious.”