(Reuters) - The United States will begin screening efforts at three U.S. airports to detect travelers from the central Chinese city of Wuhan who may have symptoms of a new respiratory virus that so far has killed two people and infected 45 more, public health officials said on Friday.

FILE PHOTO: International travelers arrive at John F. Kennedy international airport in New York City, U.S., February 4, 2017. REUTERS/Brendan McDermid

The Centers for Disease Control and Prevention (CDC) said the screening at the San Francisco, New York and Los Angeles airports would begin on Friday and focus on travelers to the United States via direct or connecting flights from Wuhan.

So far, the new virus has spread outside of China to Japan and Thailand, and CDC officials said in a conference call with reporters that they expect more cases will be reported outside of China. The risk to Americans is deemed to be low, the CDC said.

Dr. Martin Cetron, director of the CDC’s Division of Global Migration and Quarantine, said the CDC will be sending about 100 additional staff to the three airports -- Los Angeles International, San Francisco International and New York’s John F. Kennedy International -- to supplement existing staff at quarantine stations located at those airports.

Under the screening procedures, travelers from Wuhan will be taken to a separate area in the airport, where they will complete a questionnaire and be checked for fever. Those with symptoms will be asked additional health- and exposure-related questions, and those needing more follow-up will be referred to a designated healthcare facility for more testing.

The CDC said it may adjust screening procedures as the outbreak investigation continues.

The Chinese virus is a coronavirus, a large family of viruses that can cause infections ranging from the common cold to severe acute respiratory syndrome, or SARS, a highly infectious virus that originated in China in 2002 and eventually traveled to 37 countries, killing 774 people.

So far, health officials do not consider the new virus from China to be as lethal as SARS, but the investigation is evolving and much is still not known about whether the virus can spread easily from person to person.

“This is the stage of the investigation where we need to proceed cautiously and be prepared for any eventuality,” Dr. Nancy Messonnier, a CDC expert in respiratory diseases, said on the conference call.

“It’s highly plausible” that there will be a case in the United States, Messonnier said. “That is why we are moving forward with this screening.”

China health officials report that most of the patients infected with the virus have had exposure to a large market where live animals were present, suggesting the virus is new and has jumped from animals to humans.

It is still not clear how well the virus can be transmitted, but there are indications of some limited spread from person-to-person, CDC officials said.

The World Health Organization this week provided guidance to hospitals worldwide about infection prevention and control in case the new virus spreads. There is no specific treatment for the new virus, but antivirals are being considered.