The United States is reporting its first case of the new coronavirus that originated in Wuhan, China, and has killed at least six people.
Health officials in the northwest U.S. state of Washington said a man who returned to Seattle from Wuhan last week is hospitalized in good condition with pneumonia. They say he poses no threat to doctors or hospital staff members.
U.S. authorities are screening travelers from Wuhan at airports in New York, Los Angeles and San Francisco. The U.S. Centers for Disease Control and Prevention said they are adding Atlanta and Chicago to the list of airport screenings this week.
The United States is the fifth country to report cases of the new coronavirus, joining China, Japan, South Korea and Thailand.
The number of confirmed cases is approaching 300, and six deaths have been reported in Wuhan. Most of the fatalities are in patients 60 years and older.
China's National Health Commission says it now knows the virus can be transmitted person-to-person and not just from animals to people.
Chinese and U.S. health officials are particularly concerned because as many as 1.4 billion Chinese plan to travel across the country and overseas for the Lunar New Year holiday that starts Saturday.
Chinese health experts say they know little about the new strain, dubbed 2019-nCoV. They suspect the outbreak started in a Wuhan seafood market, which also sold other animals such as poultry, bats, marmots, and wild game meat.
The World Health Organization says an animal source seemed to be "the most likely primary source" with "some limited human-to-human transmission occurring between close contacts." The WHO is to hold an emergency committee Wednesday to discuss the situation.
Health officials are urging caution but say there is no reason to panic. The WHO is not recommending against travel to China, and China's National Health Commission says the current outbreak is "preventable and controllable."
A coronavirus is one of a large family of viruses that can cause illnesses ranging from the common cold to the deadly Severe Acute Respiratory Syndrome. SARS, which also started in China, killed nearly 800 people globally during an outbreak nearly 20 years ago.