NEW YORK (AP) — United States health officials announced yesterday that they will begin screening airline passengers arriving from central China for a new virus that has sickened dozens and killed two, prompting worries about a new international outbreak.

Centers for Disease Control and Prevention (CDC) officials say they will begin taking temperatures and asking about symptoms of passengers at three US airports who travelled from the outbreak city of Wuhan.

Officials estimate roughly 5,000 passengers will go through the process in the next couple of weeks at New York City’s JFK International Airport, Los Angeles International Airport and San Francisco International Airport.

The first direct flight was expected last night at JFK, and the next expected this morning in San Francisco.

More than 40 cases of the newly identified coronavirus have been confirmed in Asia, including two deaths — at least one involving a previous medical condition. Officials have said it probably spread from animals to people but haven’t been able to rule out the possibility that it spreads from person to person.

So far, the risk to the American public is deemed to be low, but the CDC wants to be prepared and is taking precautions, Dr. Martin Cetron said.

It’s always possible a virus can mutate to become more dangerous. It’s also likely that more cases will spring up around the world, including at least one at some point in the United States, said another CDC official, Dr. Nancy Messonnier.

At least half-dozen countries in Asia have started screening incoming airline passengers from central China. The list includes Thailand and Japan, which both have reported cases of the disease in people who had come from Wuhan.

Travel is unusually heavy right now as people take trips to and from China to celebrate the Lunar New Year.

The CDC said the airport screenings are part of an effort to better detect and prevent the virus from the same family of bugs that caused an international outbreak of SARS and MERS that began in 2002 and 2012.

Late last month, doctors in central China began seeing cases of a new type of viral pneumonia in people who worked at, or visited, a food market in the suburbs of Wuhan. The most common symptoms were fever, cough and difficulty breathing.

This month, health authorities identified it as a new type of coronavirus. Coronaviruses are a large family of viruses, some of which cause the common cold; others found in bats, camels and other animals have evolved into more severe illnesses.