Passengers wear protective masks to protect against the spread of the coronavirus as they arrive at the Los Angeles International Airport on January 22. Mark Ralston/AFP/Getty Images

After a person in Los Angeles County tested positive for the Wuhan coronavirus, efforts are being ramped up to trace everyone the patient came into contact with.

The US Centers for Disease Control and Prevention (CDC) and Los Angeles International Airport are assisting in contact tracing, along with the Los Angeles County Department of Public Health.

Contact tracing is defined as the identification and follow-up of people who may have come into contact with an infected person, according to the World Health Organization.

During a press conference Sunday, Dr. Barbara Ferrer, director of the Los Angeles County Department of Public Health, said that her department is working, “with the individual who is infected, along with the airport – LAX – and CDC to identify persons who may have had close personal contact with this individual.”

Ferrer said the patient, who is a resident of Wuhan, ground zero for the outbreak, had previously transited through LAX.

The individual presented themselves to health care authorities on January 22, saying they were ill. They were assessed by health care authorities and brought to a hospital in Los Angeles, where the patient remains.

The health department provided no further details about the patient’s condition, gender or age, or how many people have been contacted through their investigation.

The agency also announced at the press conference that all travelers coming from China through LAX are currently being screened.

The Los Angeles patient is one of two confirmed cases of Wuhan coronavirus in California. The other is in Orange County. The CDC on Sunday afternoon updated the total number of confirmed coronavirus cases in the United States to five.