4th case of new coronavirus diagnosed in U.S.

The patient was a traveler from Wuhan, China, where the outbreak originated.
Mohd Rasfan / AFP - Getty Images
/ Source: NBC News

Two more cases of the new coronavirus have been diagnosed in the U.S., bringing the national total to four. The new cases are both in California — one each in Los Angeles County and Orange County — in addition to one case in Washington state and another in Chicago.

On Sunday, the Los Angeles County Department of Public Health said its patient had traveled to Wuhan, China, the epicenter of the growing outbreak. The patient has been hospitalized, but no other details about that case were made available.

The other three patients remain hospitalized in isolation, but are said to be doing well.

There is no evidence person-to-person transmission has occurred anywhere in the U.S., though health officials are monitoring close contacts of all four patients closely.

The Los Angeles County Department of Public Health said in a statement that it appears this latest case does not threaten public health, cautioning, "people should not be excluded from activities based on their race, country of origin, or recent travel if they do not have symptoms of respiratory illness."

"Because novel coronavirus is new, we are learning more each day about transmission patterns and incubation periods," Barbara Ferrer, director of the Los Angeles Department of Public Health, said in a statement. "We will keep everyone informed as more information becomes available."

Cases of the new coronavirus in China have soared to nearly 2,000 in recent days. A handful of other cases have been confirmed in other countries, including Australia, France, Japan, Singapore and Thailand.

Doctors are monitoring close contacts of all of the patients for at least 14 days for any symptoms. However, health officials said anyone who's had casual contact with infected patients — shopped in the same grocery store, for example — are at "minimal risk for developing infection."