It Begins: First U.S. Coronavirus Case of 'Unknown Origin' Confirmed in Solano County, California

Health officials on Wednesday confirmed that a new coronavirus case of unknown origin has been diagnosed in Solano County and is currently being treated in Sacramento County.

An official with the Centers for Disease Control and Prevention confirmed the diagnosis of new case of coronavirus of unknown origin late Wednesday afternoon. The California Department of Public Health then confirmed the individual is a resident of Solano County and is receiving medical care at UC Davis Medical Center in Sacramento.

According to an internal memo from UC Davis Medical Center, the patient was transferred there from another Northern California hospital on Wednesday, Feb. 19. Upon arrival, the patient had already been intubated, was on a ventilator and was given droplet protection orders because of an “undiagnosed and suspected viral condition.”

The UC Davis memo explains the delay in testing by noting that neither Sacramento County nor the city of Davis’ public health agency performs the test. The hospital had to request the CDC do it. “Since the patient did not fit the existing diagnostic criteria for Covid-19, a test was not immediately administered,” the memo says. On Sunday the CDC did the test, and UC Davis put the patient on more stringent airborne and contact infection control precautions. “Today the CDC confirmed the patient’s test was positive.”

The UC Davis memo also confirms that the hospital has treated other patients infected with Covid-19 and said that the precautions it had taken with the patient all along probably meant “minimal potential for exposure.” Nevertheless, “out of an abundance of caution, in order to assure the health and safety of our employees, we are asking a small number of employees to stay home and monitor their temperature.”

The Centers for Disease Control and Prevention (CDC) has confirmed an infection with the virus that causes COVID-19 in California in a person who reportedly did not have relevant travel history or exposure to another known patient with COVID-19.

At this time, the patient’s exposure is unknown. It’s possible this could be an instance of community spread of COVID-19, which would be the first time this has happened in the United States. Community spread means spread of an illness for which the source of infection is unknown. It’s also possible, however, that the patient may have been exposed to a returned traveler who was infected.

This case was detected through the U.S. public health system — picked up by astute clinicians. This brings the total number of COVID-19 cases in the United States to 15.

The novel coronavirus is shed in the feces of infected people, which may help explain why it’s spread so fast, according to Chinese researchers.

The finding of live virus particles in stool specimens indicates a fecal-oral route for coronavirus, which may be why it’s caused outbreaks on cruise ships with an intensity often seen with gastro-causing norovirus, which also spreads along that pathway. More than 600 Covid-19 infections were confirmed among passengers and crew aboard the Diamond Princess, the ship quarantined for two weeks in Yokohama, Japan.

“This virus has many routes of transmission, which can partially explain” its rapid spread, the Chinese Center for Disease Control and Prevention said in a report Saturday.

The agency recommends strengthening sanitation and hygiene measures to prevent fecal-oral transmission in epidemic areas. These include drinking boiled water, avoiding eating raw food, implementing separate meal systems, frequent hand-washing, disinfecting toilets, and preventing water and food contamination from patients’ stool.