Passengers from China arriving in Los Angeles, San Francisco, and New York will be screened by the for a mysterious new virus that’s killed two and sickened dozens in China.

The virus, which is similar to SARS and causes pneumonia-like symptoms, was identified late last year in , a city 700 miles south of Beijing, and has been detected in Thailand and Japan.

Most of the patients are thought to have contracted the virus from animals, but person-to-person transmission appears to be possible, albeit less common.

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Federal health officials said on Friday that they would begin screening passengers arriving at three US airports from Wuhan, China, for signs of infection from a mysterious and potentially deadly new virus.

The Centers for Disease Control and Prevention (CDC) said it would deploy about 100 staff members to San Francisco International Airport, Los Angeles International Airport, and John F. Kennedy International Airport in New York City to help screen incoming passengers.

The screenings at three airports, which receive most of the travelers from Wuhan to the US on direct and connecting flights, will start Friday evening and Saturday morning. CDC officials will look for symptoms such as coughing and difficulty breathing, and will check passengers’ temperatures using an infrared thermometer.

The new screening marks the first time that the CDC has moved to proactively check arriving travelers since the 2014 Ebola outbreak.

The new virus, called “2019-nCoV” by the CDC, is a coronavirus, the type of virus behind severe acute respiratory syndrome, or SARS.

2019-nCoV, which causes flu and pneumonia-like symptoms, was first observed late last year. The virus has killed two people and sickened dozens in China. Two cases have also been reported in Thailand, and one in Japan, both linked to travelers from Wuhan.

“Investigations into this novel coronavirus are ongoing and we are monitoring and responding to this evolving situation,” Dr. Martin Cetron, director of the CDC’s division which observes and manages global migration and quarantine needs, said in a press release.

The screenings come as millions of people are traveling across China and overseas for Lunar New Year, which starts on January 25. The World Health Organization said in a statement that additional cases in other countries were likely, “considering global travel patterns.”

More than 60,000 people arrived in the US from Wuhan, a city about 700 miles south of Beijing, in 2019, the CDC said.

Chinese health officials reported that most, but not all, of the infected people had been near a large market where livestock was present, suggesting that the virus had jumped the species barrier and been transmitted directly from the animals. Person-to-person transmission appears more difficult, CDC officials said.

Several hundred healthcare workers who have treated patients have not shown any signs of contracting the virus.